2940337domain: NAppears in sequencesComposite integers k satisfying 2^d == 2^(k/d) (mod k) for all d|k and that are not Super-Poulet (A050217).at n=18A291602a(n) is the smallest n-gonal number that is a Fermat pseudoprime to base 2 (A001567), or -1 if no such number exists.at n=12A371759