A181185 Numbers k such that (2^k - 1) * k! + 1 is prime.

1, 2, 3, 6, 17, 25, 40, 45, 143, 289, 510, 524, 526, 716, 756, 1008, 1271, 1370, 3677, 7963, 9053

Offset: 1

Author

Jason Earls, Oct 09 2010

Keywords

• more
• nonn

Comments

The original motivation for this sequence was in an article by J. Earls, Horace S. Uhler and Some Numbers in His Honor, the author of which no longer wishes to make public. - N. J. A. Sloane, Apr 04 2016

Programs

PARI

is(n)=ispesudoprime((2^n-1)*n!+1) \\ Charles R Greathouse IV, Jun 13 2017

Extensions

a(20)-a(21) from Tyler Busby, Mar 10 2024