781250000domain: NAppears in sequencesExpansion of (1-x)^2/(1-5*x).at n=13A055842Numbers n such that n = Sum_{i=1..j} (phi(n) mod d(i)), where phi(n) is the Euler totient function of n and d(i) are the divisors of n.at n=24A273292Hypotenuses for which there exist exactly 11 distinct integer triangles.at n=11A290501