OFFSET
1,1
LINKS
Carlos Rivera, Puzzle 1064. GCD(2^p+1,3^p+1), The Prime Puzzles and Problems Connection.
PROG
(PARI) isok(p) = if (isprime(p), my(g=gcd(2^p+1, 3^p+1)); (g>1) && !isprime(g));
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Michel Marcus, Nov 27 2021
EXTENSIONS
a(4)-a(7) after update of Rivera link from Martin Ehrenstein, Dec 04 2021
a(8)-a(9) from Shyam Sunder Gupta, Dec 04 2021
a(10)-a(15) from Martin Ehrenstein, Dec 05 2021
STATUS
approved