86347domain: NAppears in sequencesStrong pseudoprimes to base 11.at n=22A020237Strong pseudoprimes to base 13.at n=23A020239Numbers m such that m^2 divides 2^k - 1 for some k, 0 < k <= m.at n=33A246503a(1) = 4, and for any n > 1, a(n+1) is the a(n)-th squarefree number.at n=23A356398