OFFSET
1,1
COMMENTS
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
PROG
(PARI) is(k) = {if(k == 1 || !(k%2) || isprime(k), return(0)); my(issp = 1); fordiv(k, d, if(Mod(2, d)^d != 2, issp = 0; break)); if(!issp, fordiv(k, d, if(d^2 <= k && Mod(2, k)^d != Mod(2, k)^(k/d), return(0))); 1, 0); } \\ Amiram Eldar, Apr 22 2024
CROSSREFS
KEYWORD
nonn
AUTHOR
Max Alekseyev, Aug 27 2017
STATUS
approved