%I #36 Dec 06 2015 08:02:40
%S 0,1,12,15,18,20,21,24,28,30,33,35,36,39,40,42,44,45,48,50,51,52,54,
%T 55,56,57,60,63,65,66,68,69,70,72,75,76,77,78,80,84,85,87,88,90,91,92,
%U 93,95,96,98,99,100,102,104,105,108,110,111,112,114,115,116
%N Nonprimes excluding numbers of the forms 2*p and p^i where p is a prime and i is a positive integer.
%t Select[Range@ 120, And[! PrimeQ@ #, Nand[EvenQ@ #, PrimeQ[#/2]], ! PrimePowerQ@ #] &] (* _Michael De Vlieger_, Dec 02 2015 *)
%o (PARI) isok(n) = ! (isprime(n) || (! (n%2) && isprime(n/2)) || isprimepower(n)); \\ _Michel Marcus_, Dec 02 2015
%Y Cf. A000961, A024619, A100484, A264828.
%K nonn,easy
%O 1,3
%A _Giovanni Teofilatto_, Dec 02 2015