Generalized Cullen primes of the form n•10n+1

Current data

ASCII format : n*10^n+1 Base : 10 Count : 11 Max n : 500,000 Date : 2024-10-25

1, 3, 9, 21, 363, 2161, 4839, 49521, 105994, 207777, 403765

Remarks :

The sequence A007647 in OEIS

History

• 2024-10-25: Checked n = 1 - 100000, Gary Barnes, double-check, released
• 2023-05-28: Checked n = 100000 - 500000, Mark Rodenkirch, double-check n = 100000 - 274178, released
• 2023-05-28: Found n = 403765, Mark Rodenkirch
• 2023-04-28: Reserved by Mark Rodenkirch to n = 500000
• 2023-04-23: Checked n = 2 - 100000, Mark Rodenkirch, double-check
• 2014: Checked n = 23490 - 274178, Günter Löh
• 2010-02-14: Found n = 207777, Günter Löh
• 2000-11-20: Found n = 105994, Günter Löh
• 2000: Checked n = 5228 - 23490, Wilfrid Keller
• 1999-08-18: Found n = 49521, Günter Löh
• 1989: Checked n = 1 - 5228, Harvey Dubner
• 1989: Found n = 4839, Harvey Dubner
• 1989: Found n = 2161, Harvey Dubner