OFFSET
1,1
MATHEMATICA
Select[Range[10^2], PrimeQ[(#!+2)/2] &] (* Vladimir Joseph Stephan Orlovsky, Apr 29 2008 *)
PROG
(PARI) \\ x such that (x!+2)/2 is prime
xfactpk(n, k=2) = { for(x=2, n, y = (x!+k)/k; if(isprime(y), print1(x, ", ")) ) }
(Magma) [ n: n in [1..300] | IsPrime((Factorial(n)+2) div 2) ];
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Cino Hilliard, May 18 2003
EXTENSIONS
More terms from Don Reble, Dec 08 2003
More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 03 2008
STATUS
approved