520200domain: NAppears in sequences"DHK[ 8 ]" (bracelet, identity, unlabeled, 8 parts) transform of 1,1,1,1,...at n=26A032249a(n) = n*(4n^2 - 1)^2.at n=8A069073Numbers with prime factorization p^2*q^2*r^2*s^3 where p, q, r, and s are distinct primes.at n=9A190382Numbers having exactly four non-unitary prime factors.at n=25A338541