Riesel primes of the form 121•2n-1

Current data

k , b : 121 , 2 Type : Low Count : 35 Nash : 965 Max n : 10,000,000 Date : 2021-04-08

1, 3, 21, 27, 37, 43, 91, 117, 141, 163, 373, 421, 1581, 2035, 10701, 18931, 21307, 51195, 64579, 156541, 302097, 334257, 368059, 383061, 410131, 494317, 541621, 990219, 1039965, 1526097, 1589157, 1695499, 1954243, 2033941, 4553899

History

• 2021-04-08: Checked n = 3700000 - 10000000, PrimeGrid 27121 Prime Search, released
• 2021-03-21: Checked n = 1 - 1000000, Gary Barnes, double check, results included
• 2012-02-26: Found n = 4553899, Timothy D. Winslow, PrimeGrid 27121 Prime Search, (Official announcement)
• 2009-02-13: Reserved by PrimeGrid 27121 Prime Search
• 2009?: Checked n = 3016000 - 3700000, 12121 Search, see test limit near bottom of page here
• 2007-12-02: Checked n = 1 - 3016000, 12121 Search
• 2006-01-28: Found n = 2033941, Szymon Banka, 12121 Search
• 2006-01-20: Found n = 1954243, Szymon Banka, 12121 Search
• 2005-10-25: Found n = 1589157, Frank Clowes, 12121 Search
• 2005-09-06: Found n = 1695499, Rodger M. Ewing, 12121 Search
• 2005-07-19: Found n = 1526097, Frank Clowes, 12121 Search
• 2004-11-07: Found n = 1039965, Frank Clowes, 12121 Search
• 2004-08-13: Found n = 990219, Michael E. Haas, 12121 Search
• 2004-07-21: Found n = 410131, Frank Clowes, 12121 Search
• 2004-06-09: Found n = 334257, Rodger M. Ewing, 12121 Search
• 2004-06-03: Found n = 494317, Michael E. Haas, 12121 Search
• 2004-06-02: Found n = 541621, Frank Clowes, 12121 Search
• 2004-06-02: Found n = 383061, JF Boyer, 12121 Search
• 2004-05-31: Found n = 368059, JF Boyer, 12121 Search
• 2004-05-27: Found n = 302097, Rodger M. Ewing, 12121 Search
• 2004-05-24: Reserved by 12121 Search