289941domain: NAppears in sequencesPseudoquadprimes: p+4 for primes p where p+4 divides p^(p+4) + 4 and p+4 is composite.at n=26A100875Pyramidal centered square numbers.at n=19A237516Fermat pseudoprimes to base 2 that are triangular.at n=14A293622Fermat pseudoprimes to base 2 that are hexagonal.at n=13A322130