4469471domain: NAppears in sequencesStrong pseudoprimes to base 2 and 5.at n=2A215568Composite numbers k == 3 (mod 4) such that (1 + i)^k == 1 - i (mod k), where i = sqrt(-1).at n=26A270697Base-2 Fermat pseudoprimes k such that the multiplicative order of 2 modulo k is odd.at n=26A367230