https://www.rieselprime.de/z/index.php?title=Aliquot_sequence&feed=atom&action=history
Aliquot sequence - Revision history
2024-03-28T10:01:12Z
Revision history for this page on the wiki
MediaWiki 1.31.1
https://www.rieselprime.de/z/index.php?title=Aliquot_sequence&diff=26920&oldid=prev
Karbon: typo
2023-02-21T19:49:23Z
<p>typo</p>
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<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 19:49, 21 February 2023</td>
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<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:<math>2^3</math></div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:<math>2^3</math></div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:<math>2^3\ *\ 5</math></div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:<math>2^3\ *\ 5</math></div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>:<math>2^5\ *\ 3</math><del class="diffchange diffchange-inline">\</del></div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>:<math>2^5\ *\ 3</math></div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>(For a more complete analysis of drivers and the conditions needed to escape a driver, see Clifford Stern's analysis [https://web.archive.org/web/20120212052357/http://www.lafn.org/~ax810/analysis.htm page] and Bill Winslow's [https://www.rechenkraft.net/aliquot/intro-analysis.html introductory analysis page].)</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>(For a more complete analysis of drivers and the conditions needed to escape a driver, see Clifford Stern's analysis [https://web.archive.org/web/20120212052357/http://www.lafn.org/~ax810/analysis.htm page] and Bill Winslow's [https://www.rechenkraft.net/aliquot/intro-analysis.html introductory analysis page].)</div></td></tr>
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Karbon
https://www.rieselprime.de/z/index.php?title=Aliquot_sequence&diff=12163&oldid=prev
Happy5214: Updating external links
2020-10-24T17:31:35Z
<p>Updating external links</p>
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<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 17:31, 24 October 2020</td>
</tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l39" >Line 39:</td>
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<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The numbers under 1000 whose sequences could be unbounded are 276, 306, 396, 552, 564, 660, 696, 780, 828, 888, 966 and 996. However, some of these sequences merge with earlier ones. For example, 396 merges with 276 because the sequence of 276 starts 276, 396... Only the lowest of the "family" of sequences is counted as a full open-end sequence, and the others are known as side-sequences. The open-end sequences under 1000 are 276, 552, 564, 660 and 966.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The numbers under 1000 whose sequences could be unbounded are 276, 306, 396, 552, 564, 660, 696, 780, 828, 888, 966 and 996. However, some of these sequences merge with earlier ones. For example, 396 merges with 276 because the sequence of 276 starts 276, 396... Only the lowest of the "family" of sequences is counted as a full open-end sequence, and the others are known as side-sequences. The open-end sequences under 1000 are 276, 552, 564, 660 and 966.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del class="diffchange diffchange-inline">There </del>are <del class="diffchange diffchange-inline">902 </del>open-end sequences under <math>10^5</math>, and <del class="diffchange diffchange-inline">9282 </del>under <math>10^6</math> <del class="diffchange diffchange-inline">as of January 23 2011</del>.</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline">As of October 24, 2020, there </ins>are <ins class="diffchange diffchange-inline">891 </ins>open-end sequences under <math>10^5<ins class="diffchange diffchange-inline"></math>, 9118 under <math>10^6</math>, 18361 under <math>2*10^6</ins></math>, and <ins class="diffchange diffchange-inline">27659 </ins>under <math><ins class="diffchange diffchange-inline">3*</ins>10^6</math>.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>(Reference: <del class="diffchange diffchange-inline">http</del>://www.<del class="diffchange diffchange-inline">mersenneforum</del>.<del class="diffchange diffchange-inline">org</del>/<del class="diffchange diffchange-inline">showpost</del>.<del class="diffchange diffchange-inline">php?p=248644&postcount=654</del>)</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>(Reference: <ins class="diffchange diffchange-inline">[https</ins>://www.<ins class="diffchange diffchange-inline">rechenkraft</ins>.<ins class="diffchange diffchange-inline">net</ins>/<ins class="diffchange diffchange-inline">aliquot/AllSeq</ins>.<ins class="diffchange diffchange-inline">html Dubslow and ChristianB's Blue Page]</ins>)</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==Drivers and guides==</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==Drivers and guides==</div></td></tr>
<tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l71" >Line 71:</td>
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<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:<math>2^5\ *\ 3</math>\</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:<math>2^5\ *\ 3</math>\</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>(For a more complete analysis of drivers and the conditions needed to escape a driver, see Clifford Stern's analysis [https://web.archive.org/web/20120212052357/http://www.lafn.org/~ax810/analysis.htm page].)</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>(For a more complete analysis of drivers and the conditions needed to escape a driver, see Clifford Stern's analysis [https://web.archive.org/web/20120212052357/http://www.lafn.org/~ax810/analysis.htm <ins class="diffchange diffchange-inline">page] and Bill Winslow's [https://www.rechenkraft.net/aliquot/intro-analysis.html introductory analysis </ins>page].)</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==External links==</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==External links==</div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">*[https://www.rechenkraft.net/aliquot/AllSeq.html Dubslow and ChristianB's Blue Page] Current status of sequences < 3e6, including reservations and progress.</ins></div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*[http://www.aliquot.de/aliquote.htm Wolfgang Creyaufmuller's site] Website devoted to extending open-ended sequences up to 100 digits.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*[http://www.aliquot.de/aliquote.htm Wolfgang Creyaufmuller's site] Website devoted to extending open-ended sequences up to 100 digits.</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>*[http://www.lafn.org/~ax810/aliquot.htm Aliquot sequences from the trenches] <del class="diffchange diffchange-inline">Updated more often than Wolfgang's site, there </del>is also a page with a detailed analysis of the mathematics behind guide/driver evolution.</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>*[<ins class="diffchange diffchange-inline">https://web.archive.org/web/20120207052648/</ins>http://www.lafn.org/~ax810/aliquot.htm Aliquot sequences from the trenches] <ins class="diffchange diffchange-inline">There </ins>is also a page with a detailed analysis of the mathematics behind guide/driver evolution.</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>*[[Wikipedia:<del class="diffchange diffchange-inline">Aliquot_sequence</del>|Aliquot sequence]]</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>*[[Wikipedia:<ins class="diffchange diffchange-inline">Aliquot sequence</ins>|Aliquot sequence]]</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>*[<del class="diffchange diffchange-inline">http</del>://www.mersenneforum.org/forumdisplay.php?f=90 Mersenneforum section on aliquot sequences]. Check [<del class="diffchange diffchange-inline">http</del>://www.mersenneforum.org/showthread.php?t=11588 this] thread for current sequence status.</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>*[<ins class="diffchange diffchange-inline">https</ins>://www.mersenneforum.org/forumdisplay.php?f=90 Mersenneforum section on aliquot sequences]. Check [<ins class="diffchange diffchange-inline">https</ins>://www.mersenneforum.org/showthread.php?t=11588 this] thread for current sequence status.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Category:Aliquot sequence]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Category:Aliquot sequence]]</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Category:Math]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Category:Math]]</div></td></tr>
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Happy5214
https://www.rieselprime.de/z/index.php?title=Aliquot_sequence&diff=12162&oldid=prev
Happy5214: Enclosing remaining formulas in <math> tags
2020-10-24T17:11:59Z
<p>Enclosing remaining formulas in <math> tags</p>
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<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 17:11, 24 October 2020</td>
</tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l2" >Line 2:</td>
<td colspan="2" class="diff-lineno">Line 2:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>An '''aliquot sequence''' is a sequence of numbers generated from an initial number using the sigma <math>\sigma(n)</math> function.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>An '''aliquot sequence''' is a sequence of numbers generated from an initial number using the sigma <math>\sigma(n)</math> function.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>The sequence is generated using the '''proper divisors''' of the number, <del class="diffchange diffchange-inline">''</del>n<del class="diffchange diffchange-inline">''</del>, which are all the divisors of the number, excluding itself. Therefore, sequences are generated thusly:</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>The sequence is generated using the '''proper divisors''' of the number, <ins class="diffchange diffchange-inline"><math></ins>n<ins class="diffchange diffchange-inline"></math></ins>, which are all the divisors of the number, excluding itself. Therefore, sequences are generated thusly:</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:<math>s_0 = n;</math></div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:<math>s_0 = n;</math></div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:<math>s_1 = \sigma(n) - n;</math></div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:<math>s_1 = \sigma(n) - n;</math></div></td></tr>
<tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l19" >Line 19:</td>
<td colspan="2" class="diff-lineno">Line 19:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==Calculating the divisors and sigma of a number==</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==Calculating the divisors and sigma of a number==</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>The naive way to find the divisors of a number are to check the numbers from 1 to <math>sqrt{n}</math> to see if they divide the number. Easy to do if the number is, say, less than 10 digits, but very slow if the number gets into the 30+ digit range.</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>The naive way to find the divisors of a number are to check the numbers from 1 to <math><ins class="diffchange diffchange-inline">\</ins>sqrt{n}</math> to see if they divide the number. Easy to do if the number is, say, less than 10 digits, but very slow if the number gets into the 30+ digit range.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>It turns out that if you know the prime factorization of a number, you can generate the sigma from that knowledge.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>It turns out that if you know the prime factorization of a number, you can generate the sigma from that knowledge.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>If you have a number, <del class="diffchange diffchange-inline">''</del>N<del class="diffchange diffchange-inline">''</del>, and its prime factorization is:</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>If you have a number, <ins class="diffchange diffchange-inline"><math></ins>N<ins class="diffchange diffchange-inline"></math></ins>, and its prime factorization is:</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:<math>N=p^{a}*q^{b}*r^{c}</math>. . .  </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:<math>N=p^{a}*q^{b}*r^{c}</math>. . .  </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>you can calculate the following product and arrive at the sum of the divisors:</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>you can calculate the following product and arrive at the sum of the divisors:</div></td></tr>
<tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l62" >Line 62:</td>
<td colspan="2" class="diff-lineno">Line 62:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===The downdriver===</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===The downdriver===</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>A special form of driver is '2', not raised to a power and unaccompanied by '3'. This form of driver is termed the '''downdriver''' because when a line factors with this driver, the sequence can decrease in size. Depending on the size of the other prime(s) in the factorization, a sequence can decrease by close to 50% for each line when driven by the downdriver. Unfortunately, the downdriver is less stable than all of the other drivers except <math>2^3\ *\ 3</math> and will be lost on the next line if a number factors as</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>A special form of driver is '2', not raised to a power and unaccompanied by '3'. This form of driver is termed the '''downdriver''' because when a line factors with this driver, the sequence can decrease in size. Depending on the size of the other prime(s) in the factorization, a sequence can decrease by close to 50% for each line when driven by the downdriver. Unfortunately, the downdriver is less stable than all of the other drivers except <math>2^3\ *\ 3</math> and will be lost on the next line if a number factors as</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>:<math>2\ *\ p</math>, where <del class="diffchange diffchange-inline">''</del>p<del class="diffchange diffchange-inline">'' </del>is of the form <math>4n+1</math></div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>:<math>2\ *\ p</math>, where <ins class="diffchange diffchange-inline"><math></ins>p<ins class="diffchange diffchange-inline"></math> </ins>is of the form <math>4n+1</math></div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Guides===</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Guides===</div></td></tr>
</table>
Happy5214
https://www.rieselprime.de/z/index.php?title=Aliquot_sequence&diff=1908&oldid=prev
Dylan14: update link on drivers (previous link is dead)
2019-04-05T18:38:57Z
<p>update link on drivers (previous link is dead)</p>
<table class="diff diff-contentalign-left" data-mw="interface">
<col class="diff-marker" />
<col class="diff-content" />
<col class="diff-marker" />
<col class="diff-content" />
<tr class="diff-title" lang="en">
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 18:38, 5 April 2019</td>
</tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l71" >Line 71:</td>
<td colspan="2" class="diff-lineno">Line 71:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:<math>2^5\ *\ 3</math>\</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:<math>2^5\ *\ 3</math>\</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>(For a more complete analysis of drivers and the conditions needed to escape a driver, see Clifford Stern's analysis [http://www.lafn.org/~ax810/analysis.htm page].)</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>(For a more complete analysis of drivers and the conditions needed to escape a driver, see Clifford Stern's analysis [<ins class="diffchange diffchange-inline">https://web.archive.org/web/20120212052357/</ins>http://www.lafn.org/~ax810/analysis.htm page].)</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==External links==</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==External links==</div></td></tr>
</table>
Dylan14
https://www.rieselprime.de/z/index.php?title=Aliquot_sequence&diff=1548&oldid=prev
Karbon: link corr.
2019-03-06T14:49:53Z
<p>link corr.</p>
<table class="diff diff-contentalign-left" data-mw="interface">
<col class="diff-marker" />
<col class="diff-content" />
<col class="diff-marker" />
<col class="diff-content" />
<tr class="diff-title" lang="en">
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 14:49, 6 March 2019</td>
</tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l28" >Line 28:</td>
<td colspan="2" class="diff-lineno">Line 28:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:<math>Sum=\frac{p^{a+1}-1}{p-1}\ *\ \frac{q^{b+1}-1}{q-1}\ *\ \frac{r^{c+1}-1}{r-1}\ *\ </math> . . .</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:<math>Sum=\frac{p^{a+1}-1}{p-1}\ *\ \frac{q^{b+1}-1}{q-1}\ *\ \frac{r^{c+1}-1}{r-1}\ *\ </math> . . .</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>Using the current factoring tools available today, [[Elliptic curve method|ECM]], [[MPQS]], and the [[General number field sieve|GNFS]] as needed, sequences can be calculated into the 100s of digits.</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>Using the current factoring tools available today, [[Elliptic curve method|ECM]], [[<ins class="diffchange diffchange-inline">Multiple polynomial quadratic sieve|</ins>MPQS]], and the [[General number field sieve|GNFS]] as needed, sequences can be calculated into the 100s of digits.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==Length of sequences and the Catalan-Dickson Conjecture==</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==Length of sequences and the Catalan-Dickson Conjecture==</div></td></tr>
<tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l76" >Line 76:</td>
<td colspan="2" class="diff-lineno">Line 76:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*[http://www.aliquot.de/aliquote.htm Wolfgang Creyaufmuller's site] Website devoted to extending open-ended sequences up to 100 digits.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*[http://www.aliquot.de/aliquote.htm Wolfgang Creyaufmuller's site] Website devoted to extending open-ended sequences up to 100 digits.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*[http://www.lafn.org/~ax810/aliquot.htm Aliquot sequences from the trenches] Updated more often than Wolfgang's site, there is also a page with a detailed analysis of the mathematics behind guide/driver evolution.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*[http://www.lafn.org/~ax810/aliquot.htm Aliquot sequences from the trenches] Updated more often than Wolfgang's site, there is also a page with a detailed analysis of the mathematics behind guide/driver evolution.</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>*[[Wikipedia:Aliquot_sequence|<del class="diffchange diffchange-inline">Aliquot_sequence</del>]]</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>*[[Wikipedia:Aliquot_sequence|<ins class="diffchange diffchange-inline">Aliquot sequence</ins>]]</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*[http://www.mersenneforum.org/forumdisplay.php?f=90 Mersenneforum section on aliquot sequences]. Check [http://www.mersenneforum.org/showthread.php?t=11588 this] thread for current sequence status.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*[http://www.mersenneforum.org/forumdisplay.php?f=90 Mersenneforum section on aliquot sequences]. Check [http://www.mersenneforum.org/showthread.php?t=11588 this] thread for current sequence status.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Category:Aliquot sequence]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Category:Aliquot sequence]]</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Category:Math]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Category:Math]]</div></td></tr>
</table>
Karbon
https://www.rieselprime.de/z/index.php?title=Aliquot_sequence&diff=1358&oldid=prev
Karbon: link corr.
2019-02-26T11:15:48Z
<p>link corr.</p>
<table class="diff diff-contentalign-left" data-mw="interface">
<col class="diff-marker" />
<col class="diff-content" />
<col class="diff-marker" />
<col class="diff-content" />
<tr class="diff-title" lang="en">
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 11:15, 26 February 2019</td>
</tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l28" >Line 28:</td>
<td colspan="2" class="diff-lineno">Line 28:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:<math>Sum=\frac{p^{a+1}-1}{p-1}\ *\ \frac{q^{b+1}-1}{q-1}\ *\ \frac{r^{c+1}-1}{r-1}\ *\ </math> . . .</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:<math>Sum=\frac{p^{a+1}-1}{p-1}\ *\ \frac{q^{b+1}-1}{q-1}\ *\ \frac{r^{c+1}-1}{r-1}\ *\ </math> . . .</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>Using the current factoring tools available today, [[ECM]], [[MPQS]], and the [[General number field sieve|GNFS]] as needed, sequences can be calculated into the 100s of digits.</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>Using the current factoring tools available today, [[<ins class="diffchange diffchange-inline">Elliptic curve method|</ins>ECM]], [[MPQS]], and the [[General number field sieve|GNFS]] as needed, sequences can be calculated into the 100s of digits.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==Length of sequences and the Catalan-Dickson Conjecture==</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==Length of sequences and the Catalan-Dickson Conjecture==</div></td></tr>
</table>
Karbon
https://www.rieselprime.de/z/index.php?title=Aliquot_sequence&diff=1266&oldid=prev
Karbon at 12:02, 19 February 2019
2019-02-19T12:02:28Z
<p></p>
<table class="diff diff-contentalign-left" data-mw="interface">
<col class="diff-marker" />
<col class="diff-content" />
<col class="diff-marker" />
<col class="diff-content" />
<tr class="diff-title" lang="en">
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 12:02, 19 February 2019</td>
</tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l28" >Line 28:</td>
<td colspan="2" class="diff-lineno">Line 28:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:<math>Sum=\frac{p^{a+1}-1}{p-1}\ *\ \frac{q^{b+1}-1}{q-1}\ *\ \frac{r^{c+1}-1}{r-1}\ *\ </math> . . .</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:<math>Sum=\frac{p^{a+1}-1}{p-1}\ *\ \frac{q^{b+1}-1}{q-1}\ *\ \frac{r^{c+1}-1}{r-1}\ *\ </math> . . .</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>Using the current factoring tools available today, [[ECM]], [[MPQS]], and the [[GNFS<del class="diffchange diffchange-inline">|Number Field Sieve</del>]] as needed, sequences can be calculated into the 100s of digits.</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>Using the current factoring tools available today, [[ECM]], [[MPQS]], and the [[<ins class="diffchange diffchange-inline">General number field sieve|</ins>GNFS]] as needed, sequences can be calculated into the 100s of digits.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==Length of sequences and the Catalan-Dickson Conjecture==</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==Length of sequences and the Catalan-Dickson Conjecture==</div></td></tr>
<tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l76" >Line 76:</td>
<td colspan="2" class="diff-lineno">Line 76:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*[http://www.aliquot.de/aliquote.htm Wolfgang Creyaufmuller's site] Website devoted to extending open-ended sequences up to 100 digits.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*[http://www.aliquot.de/aliquote.htm Wolfgang Creyaufmuller's site] Website devoted to extending open-ended sequences up to 100 digits.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*[http://www.lafn.org/~ax810/aliquot.htm Aliquot sequences from the trenches] Updated more often than Wolfgang's site, there is also a page with a detailed analysis of the mathematics behind guide/driver evolution.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*[http://www.lafn.org/~ax810/aliquot.htm Aliquot sequences from the trenches] Updated more often than Wolfgang's site, there is also a page with a detailed analysis of the mathematics behind guide/driver evolution.</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>*[<del class="diffchange diffchange-inline">http</del>:<del class="diffchange diffchange-inline">//en.wikipedia.org/wiki/</del>Aliquot_sequence <del class="diffchange diffchange-inline">Wikipedia</del>]</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>*[<ins class="diffchange diffchange-inline">[Wikipedia</ins>:Aliquot_sequence<ins class="diffchange diffchange-inline">|Aliquot_sequence]</ins>]</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*[http://www.mersenneforum.org/forumdisplay.php?f=90 Mersenneforum section on aliquot sequences]. Check [http://www.mersenneforum.org/showthread.php?t=11588 this] thread for current sequence status.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>*[http://www.mersenneforum.org/forumdisplay.php?f=90 Mersenneforum section on aliquot sequences]. Check [http://www.mersenneforum.org/showthread.php?t=11588 this] thread for current sequence status.</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>[[Category:Aliquot <del class="diffchange diffchange-inline">sequences</del>]]</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>[[Category:Aliquot <ins class="diffchange diffchange-inline">sequence</ins>]]</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Category:Math]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Category:Math]]</div></td></tr>
</table>
Karbon
https://www.rieselprime.de/z/index.php?title=Aliquot_sequence&diff=632&oldid=prev
Karbon at 00:38, 30 January 2019
2019-01-30T00:38:08Z
<p></p>
<table class="diff diff-contentalign-left" data-mw="interface">
<col class="diff-marker" />
<col class="diff-content" />
<col class="diff-marker" />
<col class="diff-content" />
<tr class="diff-title" lang="en">
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 00:38, 30 January 2019</td>
</tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l33" >Line 33:</td>
<td colspan="2" class="diff-lineno">Line 33:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Aliquot sequences can run anywhere from 1 step (sequences starting at a prime) to thousands of lines.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Aliquot sequences can run anywhere from 1 step (sequences starting at a prime) to thousands of lines.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>Sequences starting at even numbers are, as a rule, longer than sequences starting at odd numbers. This is because the '2' appearing in factorizations of even numbers persists, and can appear at higher powers, which tends to result in [[abundant <del class="diffchange diffchange-inline">numbers</del>]]. Also, the '2' can only disappear under specific circumstances, which are harder to achieve as the length of the numbers increase.</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>Sequences starting at even numbers are, as a rule, longer than sequences starting at odd numbers. This is because the '2' appearing in factorizations of even numbers persists, and can appear at higher powers, which tends to result in [[abundant <ins class="diffchange diffchange-inline">number</ins>]]<ins class="diffchange diffchange-inline">s</ins>. Also, the '2' can only disappear under specific circumstances, which are harder to achieve as the length of the numbers increase.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>The Catalan-Dickson Conjecture states that all sequences are '''bounded''', that they either terminate in a prime, a perfect number, or fall into a cycle of length 2, [[amicable <del class="diffchange diffchange-inline">numbers</del>]], or longer, [[sociable <del class="diffchange diffchange-inline">numbers</del>]], but other researchers disagree with this conjecture.</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>The Catalan-Dickson Conjecture states that all sequences are '''bounded''', that they either terminate in a prime, a perfect number, or fall into a cycle of length 2, [[amicable <ins class="diffchange diffchange-inline">number</ins>]]<ins class="diffchange diffchange-inline">s</ins>, or longer, [[sociable <ins class="diffchange diffchange-inline">number</ins>]]<ins class="diffchange diffchange-inline">s</ins>, but other researchers disagree with this conjecture.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The numbers under 1000 whose sequences could be unbounded are 276, 306, 396, 552, 564, 660, 696, 780, 828, 888, 966 and 996. However, some of these sequences merge with earlier ones. For example, 396 merges with 276 because the sequence of 276 starts 276, 396... Only the lowest of the "family" of sequences is counted as a full open-end sequence, and the others are known as side-sequences. The open-end sequences under 1000 are 276, 552, 564, 660 and 966.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The numbers under 1000 whose sequences could be unbounded are 276, 306, 396, 552, 564, 660, 696, 780, 828, 888, 966 and 996. However, some of these sequences merge with earlier ones. For example, 396 merges with 276 because the sequence of 276 starts 276, 396... Only the lowest of the "family" of sequences is counted as a full open-end sequence, and the others are known as side-sequences. The open-end sequences under 1000 are 276, 552, 564, 660 and 966.</div></td></tr>
</table>
Karbon
https://www.rieselprime.de/z/index.php?title=Aliquot_sequence&diff=630&oldid=prev
Karbon: restored
2019-01-30T00:24:18Z
<p>restored</p>
<p><b>New page</b></p><div>==Definiton==<br />
An '''aliquot sequence''' is a sequence of numbers generated from an initial number using the sigma <math>\sigma(n)</math> function.<br />
<br />
The sequence is generated using the '''proper divisors''' of the number, ''n'', which are all the divisors of the number, excluding itself. Therefore, sequences are generated thusly:<br />
:<math>s_0 = n;</math><br />
:<math>s_1 = \sigma(n) - n;</math><br />
:<math>s_2 = \sigma(s_1) - s_1</math><br />
: .<br />
: .<br />
:<math>s_n = \sigma(s_{n-1}) - s_{n-1}</math><br />
<br />
So the sequence starting at 10 would be:<br />
:<math>s_0\ =\ 10,\ \sigma(10)=1\ +\ 2\ +\ 5\ +\ 10</math><br />
:<math>s_1\ =\ 18\ -\ 10\ =\ 8,\ \sigma(8)\ =\ 1\ +\ 2\ +\ 4\ +\ 8</math><br />
:<math>s_2\ =\ 15\ -\ 8\ =\ 7,\ \sigma(7)\ =\ 1\ +\ 7</math><br />
:<math>s_3\ =\ 8\ -\ 7\ =\ 1,\ \sigma(1)\ =\ 1</math><br />
:<math>s_4\ =\ 1\ -\ 1\ =\ 0</math><br />
and therefore terminates. The sequence is usually defined as ending when the result of the previous step is a prime, so the sequence starting at 10 ends at line 2 with the prime 7.<br />
<br />
==Calculating the divisors and sigma of a number==<br />
The naive way to find the divisors of a number are to check the numbers from 1 to <math>sqrt{n}</math> to see if they divide the number. Easy to do if the number is, say, less than 10 digits, but very slow if the number gets into the 30+ digit range.<br />
<br />
It turns out that if you know the prime factorization of a number, you can generate the sigma from that knowledge.<br />
<br />
If you have a number, ''N'', and its prime factorization is:<br />
:<math>N=p^{a}*q^{b}*r^{c}</math>. . . <br />
you can calculate the following product and arrive at the sum of the divisors:<br />
:<math>Sum=\frac{p^{a+1}-1}{p-1}\ *\ \frac{q^{b+1}-1}{q-1}\ *\ \frac{r^{c+1}-1}{r-1}\ *\ </math> . . .<br />
<br />
Using the current factoring tools available today, [[ECM]], [[MPQS]], and the [[GNFS|Number Field Sieve]] as needed, sequences can be calculated into the 100s of digits.<br />
<br />
==Length of sequences and the Catalan-Dickson Conjecture==<br />
Aliquot sequences can run anywhere from 1 step (sequences starting at a prime) to thousands of lines.<br />
<br />
Sequences starting at even numbers are, as a rule, longer than sequences starting at odd numbers. This is because the '2' appearing in factorizations of even numbers persists, and can appear at higher powers, which tends to result in [[abundant numbers]]. Also, the '2' can only disappear under specific circumstances, which are harder to achieve as the length of the numbers increase.<br />
<br />
The Catalan-Dickson Conjecture states that all sequences are '''bounded''', that they either terminate in a prime, a perfect number, or fall into a cycle of length 2, [[amicable numbers]], or longer, [[sociable numbers]], but other researchers disagree with this conjecture.<br />
<br />
The numbers under 1000 whose sequences could be unbounded are 276, 306, 396, 552, 564, 660, 696, 780, 828, 888, 966 and 996. However, some of these sequences merge with earlier ones. For example, 396 merges with 276 because the sequence of 276 starts 276, 396... Only the lowest of the "family" of sequences is counted as a full open-end sequence, and the others are known as side-sequences. The open-end sequences under 1000 are 276, 552, 564, 660 and 966.<br />
<br />
There are 902 open-end sequences under <math>10^5</math>, and 9282 under <math>10^6</math> as of January 23 2011.<br />
<br />
(Reference: http://www.mersenneforum.org/showpost.php?p=248644&postcount=654)<br />
<br />
==Drivers and guides==<br />
===Perfect numbers===<br />
During the calculation of a sequence, several prime factorization structures can tend to persist. The most stable form of these is called a '''driver'''. This is because they tend to drive the sequence higher at every step. Of the drivers, the worst ones are the [[perfect number]]s:<br />
:<math>2^ \ \ *\ 3</math><br />
:<math>2^2\ *\ 7</math><br />
:<math>2^4\ *\ 31</math><br />
:<math>2^6\ *\ 127</math><br />
<br />
===The other drivers===<br />
The other drivers are<br />
:<math>2^3\ *\ 3</math><br />
:<math>2^3\ *\ 3\ *\ 5</math><br />
:<math>2^5\ *\ 3\ *\ 7</math><br />
:<math>2^9\ *\ 3\ *\ 11\ *\ 31</math><br />
<br />
The last of these has only been seen a couple of times 'in the wild'.<br />
<br />
===The downdriver===<br />
A special form of driver is '2', not raised to a power and unaccompanied by '3'. This form of driver is termed the '''downdriver''' because when a line factors with this driver, the sequence can decrease in size. Depending on the size of the other prime(s) in the factorization, a sequence can decrease by close to 50% for each line when driven by the downdriver. Unfortunately, the downdriver is less stable than all of the other drivers except <math>2^3\ *\ 3</math> and will be lost on the next line if a number factors as<br />
:<math>2\ *\ p</math>, where ''p'' is of the form <math>4n+1</math><br />
<br />
===Guides===<br />
Guides are less persistent than drivers, but can also tend to appear in subsequent lines of a sequence. Some examples of guides are:<br />
:<math>2^2</math><br />
:<math>2^3</math><br />
:<math>2^3\ *\ 5</math><br />
:<math>2^5\ *\ 3</math>\<br />
<br />
(For a more complete analysis of drivers and the conditions needed to escape a driver, see Clifford Stern's analysis [http://www.lafn.org/~ax810/analysis.htm page].)<br />
<br />
==External links==<br />
*[http://www.aliquot.de/aliquote.htm Wolfgang Creyaufmuller's site] Website devoted to extending open-ended sequences up to 100 digits.<br />
*[http://www.lafn.org/~ax810/aliquot.htm Aliquot sequences from the trenches] Updated more often than Wolfgang's site, there is also a page with a detailed analysis of the mathematics behind guide/driver evolution.<br />
*[http://en.wikipedia.org/wiki/Aliquot_sequence Wikipedia]<br />
*[http://www.mersenneforum.org/forumdisplay.php?f=90 Mersenneforum section on aliquot sequences]. Check [http://www.mersenneforum.org/showthread.php?t=11588 this] thread for current sequence status.<br />
[[Category:Aliquot sequences]]<br />
[[Category:Math]]</div>
Karbon