%I #17 Jan 10 2017 23:04:01

%S 4,5,6,13,21,25,32,40,61,97,147,324,325,348,369,1290,1342,3167,6612,

%T 8176,10990

%N Numbers n for which (4+n!)/4 is prime.

%C For primes of the form (4+k!)/4, see A139060.

%C a(22) > 25000. - _Robert Price_, Jan 10 2017

%t a = {}; Do[If[PrimeQ[(n! + 4)/4], AppendTo[a, n]], {n, 1, 500}]; a

%t Select[Range[500],PrimeQ[(4+#!)/4]&] (* _Harvey P. Dale_, Mar 24 2011 *)

%o (PARI) for(n=4,1e3,if(ispseudoprime(n!/4+1),print1(n", "))) \\ _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, A139068, A137390, A139070, A139071, A139072.

%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 More terms from _Serge Batalov_, Feb 18 2015

%E a(19) - a(21) from _Robert Price_, Jan 10 2017