Riesel primes of the form 421•2n-1

Reserved! This sequence is currently part of Multi Reservation 8: NPLB Drive 17.

Current data

k , b : 421 , 2 Count : 38 Nash : 1823 Max n : 2,820,000 Date : 2024-03-09 Reserved : No Prime Left BehindNo Prime Left Behind/Reserved

7, 11, 13, 17, 19, 43, 73, 109, 119, 121, 139, 209, 227, 889, 1201, 1753, 1915, 2447, 3973, 6037, 7279, 12157, 13573, 14527, 18695, 20267, 27901, 29155, 41227, 136273, 147125, 227035, 403129, 595801, 696385, 706219, 2324375, 2597273

History

• 2023-09-11: Found n = 2597273, Florian Piesker
• 2023-03-15: Found n = 2324375, Florian Piesker
• 2022-08-10: Checked to n = 2000000, NPLB Drive 13, released
• 2022-08-09: Reserved by NPLB Drive 17, for 2000000<n<3000000
• 2011-08-04: Reserved by NPLB Drive 13, for 1000000<n<2000000
• 2010-11-11: Checked to n = 1000000, NPLB Drive 5
• 2009-08-05: Found n = 706219, Vaughan Davies
• 2009-06-17: Found n = 696385, Gary Barnes
• 2008-12-22: Checked to n = 600000, NPLB Drive 1
• 2008-12-20: Found n = 595801, Gary Barnes
• 2008-12-19: Reserved by NPLB Drive 5, for 600000<n<1000000
• 2008-03-25: Checked to n = 333200, NPLB Drive 2
• 2008-03-09: Found n = 403129, James P. Burt
• 2008-01-22: Reserved by NPLB Drive 2, for 260000<=n<=333200
• 2008-01-21: Reserved by NPLB Drive 1, for 333201<=n<=600000
• 2005-01-09: Found n = 227035, Peter O'braian
• 2002-01-05: Found n = 136273, Kimmo Herranen