313929domain: NAppears in sequencesNumbers k such that sum of divisors of k^2 is a square.at n=22A008847Odd numbers n such that sigma(sigma(n^2)) is odd.at n=5A234641E.g.f. A(x) satisfies: A(x) = exp( Integral A(x)^3 * Integral 1/A(x)^9 dx dx ).at n=5A258658