A139063 - OEIS

%I #19 Nov 20 2016 10:24:14

%S 3,4,10,11,13,14,17,21,82,115,165,167,173,174,208,225,380,655,1187,

%T 2000,2568,3010,4542,8750,12257,12601,24083

%N Numbers k for which (6+k!)/6 is prime.

%C For primes of the form (6+k!)/6, see A139062.

%C a(28) > 25000. - _Robert Price_, Nov 20 2016

%t a = {}; Do[If[PrimeQ[(n! + 6)/6], AppendTo[a, n]], {n, 1, 500}]; a

%o (PARI) for(k=3,1e3,if(ispseudoprime(k!/6+1),print1(k", "))) \\ _Charles R Greathouse IV_, Jul 15 2011

%Y Cf. A082672, A089085, A089130, A117141, A007749, A139056, A139057, A139058, A139059, A139060, A139061, A139061, A139062, A139063, A139064, A139065, A139066, A020458.

%Y 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).

%K nonn

%O 1,1

%A _Artur Jasinski_, Apr 07 2008

%E a(18) and a(19) from _Robert Israel_, May 19 2014

%E More terms from _Serge Batalov_, Feb 18 2015

%E a(24)-a(27) from _Robert Price_, Nov 20 2016