172250domain: NAppears in sequencesNumbers n such that n | Sigma_2(n) + Phi(n)^2.at n=11A055696Numbers k such that k | sigma_6(k) + phi(k)^6.at n=23A055700Numbers n that are the hypotenuse of exactly 31 distinct integer-sided right triangles, i.e., n^2 can be written as a sum of two squares in 31 ways.at n=28A097244