25937425625domain: NAppears in sequencesLeast number of the form x^n + y^n that is the sum of two positive squares in exactly n ways (x, y > 0).at n=9A274485Sum of the 10th powers of the primes dividing n.at n=21A351198a(n) = n^10 * Sum_{p|n, p prime} 1/p^10.at n=21A351262