Generalized Cullen primes of the form n•18n+1

Current data

ASCII format : n*18^n+1 Base : 18 Count : 16 Max n : 1,000,000 Date : 2024-10-25

1, 3, 21, 23, 842, 1683, 3401, 16839, 49963, 60239, 150940, 155928, 219525, 342091, 353901, 612497

Remarks :

The sequence A007648 in OEIS

History

• 2024-10-25: Checked n = 1 - 100000, Gary Barnes, double-check, released
• 2023-05-20: Checked to n = 1000000, Ryan Propper
• 2023-05-20: Found n = 612497, Ryan Propper
• 2023-05-20: Found n = 353901, Ryan Propper
• 2023-05-20: Found n = 342091, Ryan Propper
• 2023-05-20: Found n = 219525, Ryan Propper
• 2023-05-18: Reserved by Ryan Propper to n = 1000000
• 2023-04-25: Checked n = 2 - 100000, Mark Rodenkirch, double-check
• 2014: Checked n = 4441 - 218779, Günter Löh
• ?: Found n = 155928, Günter Löh
• ?: Found n = 150940, Günter Löh
• 2002-05-20: Found n = 60239, Günter Löh
• 2000-11-02: Found n = 49963, Günter Löh
• 2000-05-15: Found n = 16839, Günter Löh
• 2000: Checked n = 3054 - 4441, Wilfrid Keller
• 2000-02: Found n = 3401, Wilfrid Keller
• 1989: Checked n = 1 - 3054, Harvey Dubner
• 1989: Found n = 1683, Harvey Dubner
• 1989: Found n = 842, Harvey Dubner