Riesel primes of the form 221•2n-1

Current data

k , b : 221 , 2 Type : Low Count : 13 Nash : 418 Max n : 2,000,000 Date : 2021-02-13

2, 6, 42, 354, 402, 914, 1562, 10382, 34986, 81042, 104846, 730986, 749166

History

• 2021-02-13: Checked to n = 2000000, Gary Barnes, double-check n=1000000-1850000, released
• 2021-02-13: Reserved by Gary Barnes
• 2014-09-13: Checked to n = 1850000, Steven Tjung
• 2013-08-22: Checked to n = 1500000, Steven Tjung
• 2012-08-19: Checked to n = 1100000, Steven Tjung
• 2009-12-05: Checked to n = 1100000, Steven Tjung
• 2009-05-15: Checked to n = 1050000, Steven Tjung
• 2009-04-06: none, Steven Tjung
• 2009-02-12: Checked to n = 1000000, Steven Tjung
• 2008-12-03: Checked to n = 860000, Michael Curtis
• 2008-10-26: Found n = 749166, Michael Curtis
• 2008-03-15: Reserved by Michael Curtis
• 2008-03-01: Checked to n = 740000, Borys Jaworski, released
• 2008-02-25: Found n = 730986, Borys Jaworski
• 2008-02-09: Checked to n = 700000, Borys Jaworski
• 2008-02-03: Checked to n = 690000, Borys Jaworski
• 2008-01-12: Checked to n = 650000, Borys Jaworski
• 2008-01-06: Checked to n = 640000, Borys Jaworski
• 2007-10-01: Reserved by Borys Jaworski
• 1998-11-30: Found n = 34986, Wilfrid Keller