OFFSET
1,1
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..1175
MATHEMATICA
a = {}; Do[c = (2^Prime[x] + 1)/3; If[PrimeQ[c] == False, AppendTo[a, x]], {x, 2, 300}]; a
Select[Range[2, 100], !PrimeQ[(2^Prime[#]+1)/3]&] (* Harvey P. Dale, Nov 24 2013 *)
PROG
(PARI) isok(n) = (n!=1) && !isprime((2^prime(n)+1)/3); \\ Michel Marcus, Jul 07 2018
CROSSREFS
KEYWORD
nonn
AUTHOR
Artur Jasinski, Feb 09 2007
STATUS
approved