%I #16 Sep 24 2024 17:37:57
%S 2,3,5,11,23
%N Primes of the form n!! + (n+1)!!.
%C These are all primes of the form n!! + (n+1)!! Corresponding values of n are 0, 1, 2, 3, 4. At n>4, n!! + (n+1)!! is always composite, cf. A118333.
%C Apparently also the set of primes p(n) such that p(n)^2 - 2^n is prime. - _Irina Gerasimova_, May 09 2013
%t Select[Array[#!! + (# + 1)!! &, 12, 0], PrimeQ] (* _James C. McMahon_, Sep 24 2024 *)
%Y Cf. A118333.
%K fini,full,nonn
%O 1,1
%A _Zak Seidov_, Apr 23 2006