A092791 Numbers k such that (k-1)! + k is prime.

1, 2, 3, 5, 7, 11, 53, 6823, 30839

Offset: 1

Author

Cino Hilliard, Apr 15 2004

Keywords

• nonn

Comments

All terms beyond the first must be prime. [Charles R Greathouse IV, Apr 19 2013]

a(10) > 37000. - Giovanni Resta, May 04 2013

Crossrefs

Cf. A073308.

Programs

Mathematica

Select[Range[80], PrimeQ[(# - 1)! + #] &] (* Jayanta Basu, Apr 19 2013 *)

PARI

pm1factpp(n) = { forprime(p=1,n, c=0; y=(p-1)!+p;if(isprime(y),print1(p",")) ) }

Formula

a(n) = A073308(n) + 1. - Michael S. Branicky, May 06 2025

Extensions

a(8)-a(9) from Giovanni Resta, May 04 2013