Riesel primes of the form 197•2n-1

Current data

k , b : 197 , 2 Count : 38 Nash : 1573 Max n : 5,500,000 Date : 2025-06-21

2, 16, 20, 22, 40, 82, 112, 178, 230, 302, 304, 328, 374, 442, 472, 500, 580, 694, 1264, 1634, 1784, 3080, 5722, 7174, 8908, 18502, 18746, 39094, 99338, 170066, 202534, 325610, 510940, 569222, 635042, 825188, 1796284, 4765318

History

• 2025-06-21: Reservation dropped, Tanel Liiv
• 2023-11-01: Checked to n = 5500000, Tanel Liiv
• 2021-10-01: Checked to n = 5000000, Tanel Liiv
• 2021-04-29: Found n = 4765318, Tanel Liiv
• 2021-02-02: Checked to n = 4600000, Tanel Liiv
• 2020-09-21: Checked to n = 4200000, Tanel Liiv
• 2020-06-11: Checked to n = 3700000, Tanel Liiv
• 2020-03-13: Reserved by Tanel Liiv from n=3020000
• 2020-03-13: Checked to n = 3020000, Michael Curtis, released
• 2017-07-03: Checked to n = 3000000, Michael Curtis
• 2016-01-03: Checked to n = 2500000, Michael Curtis
• 2015-04-01: Checked to n = 2000000, Michael Curtis
• 2015-02-17: Found n = 1796284, Michael Curtis
• 2014-10-05: Checked to n = 1640000, Michael Curtis
• 2014-03-07: Checked to n = 1530000, Michael Curtis
• 2013-12-07: Checked to n = 1500000, Michael Curtis
• 2013-06-11: Checked to n = 1440000, Michael Curtis
• 2012-05-04: Checked to n = 1400000, Michael Curtis
• 2011-04-27: Reserved by Michael Curtis
• 2009-02-13: Checked to n = 1200000, Michael Curtis, released
• 2008-07-14: Checked to n = 1140000, Michael Curtis
• 2008-03-15: Checked to n = 1100000, Michael Curtis
• 2008-02-22: Checked to n = 1030000, Michael Curtis
• 2008-01-13: Checked to n = 970000, Michael Curtis
• 2007-11-21: none, Michael Curtis
• 2007-10-24: none, Michael Curtis
• 2007-09-10: Checked to n = 950000, Michael Curtis
• 2007-07-30: Checked to n = 950000, Michael Curtis
• 2007-07-18: Checked to n = 882000, Michael Curtis
• 2007-07-01: Found n = 825188, Michael Curtis
• 2007-05-06: Found n = 635042, Michael Curtis
• 2007-02-16: Found n = 569222, Michael Curtis
• 2007-02-02: Found n = 510940, Michael Curtis
• 2006-11-13: Found n = 325610, Michael Curtis
• 2004-07-26: Found n = 202534, Mark Anderson
• 2004-07-09: Found n = 170066, Mark Anderson