**Latest news:** |

2018-12-07: A new Mersenne prime 2^{82589933}-1 was found! |

2018-03-13: New page for Carol/Kynea Search included (with display-options, all bases≤3000, statistics) |

2017-12-26: A new Mersenne prime 2^{77232917}-1 was found! |

2016-01-07: A new Mersenne prime 2^{74207281}-1 was found! |

2015-05-18: Tested 2000 < *k* < 2300, 600k < *n* < 700k: 61 primes found (35 new); partly doublecheck of RPS Drive #11 |

2015-03-10: Pages for Home Prime Base 12 and Home Prime Base 16 included, thanks to E.Robinson |

2014-10-16: Tested missing pairs of Free-DC Drive #1 for 3400 < *k* <4000, 400000 ≤ *n* ≤ 540000: 75 primes found, 25 new |

2014-10-04: Riesel Prime 502573·2^{7181987}-1 found by D.Iakovlev (PrimeGrid) |

2014-10-02: Riesel Prime 402539·2^{7173024}-1 found by W.Darimont (PrimeGrid) |

2014-08-13: NEW: Guestbook for testing! |

2014-08-04: I've included 946 new primes, 70 verified in the range 3000 < *k* < 4000, 200k ≤ *n* ≤ 400k |

2014-07-03: New page for Biggest Puzzles included (299 Puzzles with 5000 pieces and more) |

2014-06-04: New page for RPS 3rd MegabitDrive included |

2014-01-31: New page for RPS Drive #12 included |

2014-01-31: Page for RPS Drive #11 completed |

2013-12-27: Riesel Prime 40597·2^{6808509}-1 found by F.Meador (PrimeGrid) |

2013-11-04: New page for NPLB Mini Drive #5 included |

2013-10-11: Riesel Prime 304207·2^{6643565}-1 found by R.Ready (PrimeGrid) |

2013-10-09: Riesel Prime 398023·2^{6418059}-1 found by V.Volynsky (PrimeGrid) |

2013-09-19: Values for 15000 ≤ *n* < 17000 from R.Pierrard added to the page First odd *k* twin for *k*·2^{n}-1 |

2013-09-05: 2714 new primes (out of 13771) for 3010 < *k* < 4000, *n* ≤ 200000 from O.T.Santandreu inserted |

2013-06-10: Page for NPLB Drive #10 completed |

2013-03-22: New page for OEIS A057207 included |

2013-03-14: New page for Home Prime Base 9 and HP-Overview included |

2013-02-28: New page for NPLB Maxi Drive #1 included |

2013-01-25: A new Mersenne prime 2^{57885161}-1 was found! |

2012-11-23: On page First odd k with Sophie-Germain values for 4001 ≤ *n* ≤ 10000 added |

2012-10-24: New page for Home Prime Base 8 included |

2012-10-22: New page for Home Prime Base 7 included |

2012-08-04: New page for Home Prime Base 5 included |

2012-07-03: New page for Home Prime Base 4 included |

older entries: see History |