5173169domain: NAppears in sequencesNumbers k having at least one prime factor p such that p^2 divides 2^(k-1) - 1.at n=14A291194Numbers k such that gcd(k^2, 2^(k-1) - 1) > k.at n=10A331021Squarefree base-2 Fermat pseudoprimes divisible by a Wieferich prime.at n=1A353221