Currently there may be errors shown on top of a page, because of a missing Wiki update (PHP version and extension DPL3).
Navigation
Topics Help • Register • News • History • How to • Sequences statistics • Template prototypes

Difference between revisions of "Williams prime"

From Prime-Wiki
Jump to: navigation, search
(corr.)
(correction of limits)
Line 1: Line 1:
 
==Definition==
 
==Definition==
A '''Williams number''' is a [[natural number]] of the form {{Kbn|(b-1)|b|n}} for integers ''b ≥ 2'' and ''n ≥ 1.
+
A '''Williams number''' is a [[natural number]] of the form {{Kbn|(b-1)|b|n}} for integers ''b'' ≥ 2 and ''n'' ≥ 1.
  
 
A '''Williams prime''' is a Williams number which is [[prime]].
 
A '''Williams prime''' is a Williams number which is [[prime]].
Line 9: Line 9:
 
Lists of primes for bases ''b'' and ''n''-values can be found here:
 
Lists of primes for bases ''b'' and ''n''-values can be found here:
 
{| class="wikitable"
 
{| class="wikitable"
! Type !! Category !! List<br>table <ref>The list table of any type contains only bases which are included as a separate page.</ref> !! List<br>smallest <ref>The list of smallest primes of any base is an ASCII file for 2 &le; ''b'' &le; 1024. Any unknown value is given with the search range in brackets or empty.</ref>
+
! Type !! Category !! Table <ref>The table contains only bases which are included as a separate page.</ref> !! Smallest <ref>The list of smallest primes of any base is an ASCII file for 2 ''b'' 1024. For unknown values only the base is given.</ref>
 
|-
 
|-
| MM: {{Kbn|(b-1)|b|n}} || [[:Category:Williams prime MM|here]] ||[[Williams prime MM table|here]] || [[Williams prime MM least|here]]
+
| MM: {{Kbn|(b-1)|b|n}} || [[:Category:Williams prime MM|here]] ||[[Williams prime MM table|here]] || [[Williams prime MM least|here]]<ref>The list contains values for 2 ≤ ''b'' ≤ 2049.</ref>
 
|-
 
|-
 
| MP: {{Kbn|+|(b-1)|b|n}} || [[:Category:Williams prime MP|here]] ||[[Williams prime MP table|here]] || [[Williams prime MP least|here]]
 
| MP: {{Kbn|+|(b-1)|b|n}} || [[:Category:Williams prime MP|here]] ||[[Williams prime MP table|here]] || [[Williams prime MP least|here]]
Line 17: Line 17:
 
| PM: {{Kbn|(b+1)|b|n}} || [[:Category:Williams prime PM|here]] ||[[Williams prime PM table|here]] || [[Williams prime PM least|here]]
 
| PM: {{Kbn|(b+1)|b|n}} || [[:Category:Williams prime PM|here]] ||[[Williams prime PM table|here]] || [[Williams prime PM least|here]]
 
|-
 
|-
| PP: {{Kbn|+|(b+1)|b|n}} || [[:Category:Williams prime PP|here]] ||[[Williams prime PP table|here]] || [[Williams prime PP least|here]] <ref>Values for bases ''b'' == 1 mod 3 are always divisible by 3, so not listed here.</ref>
+
| PP: {{Kbn|+|(b+1)|b|n}} || [[:Category:Williams prime PP|here]] ||[[Williams prime PP table|here]] || [[Williams prime PP least|here]] <ref>Values for bases ''b'' 1 mod 3 are always divisible by 3, so not listed here.</ref>
 
|}
 
|}
  
Line 26: Line 26:
 
*H. C. Williams: [http://matwbn.icm.edu.pl/ksiazki/aa/aa39/aa3912.pdf "The primality of certain integers of the form 2Ar^n-1"], Acta Arith. 39 (1981), 7-17
 
*H. C. Williams: [http://matwbn.icm.edu.pl/ksiazki/aa/aa39/aa3912.pdf "The primality of certain integers of the form 2Ar^n-1"], Acta Arith. 39 (1981), 7-17
 
*A. Stein, H. C. Williams: [https://www.ams.org/journals/mcom/2000-69-232/S0025-5718-00-01212-6/S0025-5718-00-01212-6.pdf "Explicit primality criteria for (p−1)p<sup>n</sup>−1"], Math. Comp. 69 (2000), 1721-1734
 
*A. Stein, H. C. Williams: [https://www.ams.org/journals/mcom/2000-69-232/S0025-5718-00-01212-6/S0025-5718-00-01212-6.pdf "Explicit primality criteria for (p−1)p<sup>n</sup>−1"], Math. Comp. 69 (2000), 1721-1734
*Steven Harvey: [http://harvey563.tripod.com/wills.txt Search for Williams primes]: only Type MM {{Kbn|(b-1)|b|n}} for 3 ≤ ''b'' ≤ 2049, 1 ≤ ''n'' ≤ 512 and some higher (2006-2019)
+
*Steven Harvey: [http://harvey563.tripod.com/wills.txt Search for Williams primes]: only Type MM {{Kbn|(b-1)|b|n}} for 3 ≤ ''b'' ≤ 1019, 1 ≤ ''n'' ≤ 512 and 1020 ≤ ''b'' ≤ 2049, 1 ≤ ''n'' ≤ 100 and some higher (2006-2019)
 
*Mauro Fiorentini: [http://www.bitman.name/math/table/484 Type MM], [http://www.bitman.name/math/table/477 Type MP], [http://www.bitman.name/math/table/471 Type PM], [http://www.bitman.name/math/table/474 Type PP] for 0 ≤ ''n'' ≤ 1000 (mostly) and 1 ≤ ''b'' ≤ 1000 (2016)
 
*Mauro Fiorentini: [http://www.bitman.name/math/table/484 Type MM], [http://www.bitman.name/math/table/477 Type MP], [http://www.bitman.name/math/table/471 Type PM], [http://www.bitman.name/math/table/474 Type PP] for 0 ≤ ''n'' ≤ 1000 (mostly) and 1 ≤ ''b'' ≤ 1000 (2016)
 
*Eric Chen: [https://www.mersenneforum.org/showthread.php?t=21818 Thread] at [[MersenneForum]] including dual forms for 0 ≤ ''n'' ≤ 5000 and 1 ≤ ''b'' ≤ 64 and some higher (2016-2019)
 
*Eric Chen: [https://www.mersenneforum.org/showthread.php?t=21818 Thread] at [[MersenneForum]] including dual forms for 0 ≤ ''n'' ≤ 5000 and 1 ≤ ''b'' ≤ 64 and some higher (2016-2019)

Revision as of 11:40, 4 June 2019

Definition

A Williams number is a natural number of the form (b-1)bn-1 for integers b ≥ 2 and n ≥ 1.

A Williams prime is a Williams number which is prime.

Generalization

Varying both signs, there're four different types of numbers similiar to Williams numbers.

Lists of primes for bases b and n-values can be found here:

Type Category Table [1] Smallest [2]
MM: (b-1)bn-1 here here here[3]
MP: (b-1)bn+1 here here here
PM: (b+1)bn-1 here here here
PP: (b+1)bn+1 here here here [4]

Notes

  1. The table contains only bases which are included as a separate page.
  2. The list of smallest primes of any base is an ASCII file for 2 ≤ b ≤ 1024. For unknown values only the base is given.
  3. The list contains values for 2 ≤ b ≤ 2049.
  4. Values for bases b ≡ 1 mod 3 are always divisible by 3, so not listed here.

External links

Number classes
General numbers
Special numbers
Prime numbers