A139071 Numbers k for which (10+k!)/10 is prime.

5, 6, 11, 12, 15, 23, 26, 37, 45, 108, 112, 129, 137, 148, 172, 248, 760, 807, 975, 1398, 5231, 8765, 24182

Offset

1,1

Comments

Primes of the form (10+k!)/10 see A139070.

a(24) > 25000. - Robert Price, Nov 08 2016

Links

Table of n, a(n) for n=1..23.

Mathematica

a = {}; Do[If[PrimeQ[(n! + 10)/10], AppendTo[a, n]], {n, 1, 500}]; a

Prog

(PARI) for(k=5, 1e3, if(ispseudoprime(k!/10+1), print1(k", "))) \\ Charles R Greathouse IV, Jul 15 2011

Crossrefs

Cf. A082672, A089085, A089130, A117141, A007749, A139056, A139057, A139058, A139059, A139060, A139061, A139061, A139062, A139063, A139064, A139065, A139066, A020458, A139068, A137390, A139070, A139071, A139072.

Cf. n!/m-1 is a prime: A002982, A082671, A139056, A139199-A139205; n!/m+1 is a prime: A002981, A082672, A089085, A139061, A139058, A139063, A139065, A151913, A137390, A139071 (1<=m<=10).

Sequence in context: A120517 A246395 A337399 * A092296 A046608 A228357

Adjacent sequences: A139068 A139069 A139070 * A139072 A139073 A139074

Keyword

nonn

Author

Artur Jasinski, Apr 07 2008

Extensions

More terms from Serge Batalov, Feb 18 2015

a(22)-a(23) from Robert Price, Nov 08 2016

Status

approved