94240domain: NAppears in sequencesNumbers n such that n | (sigma_5(n) - phi(n)^5).at n=28A055699Numbers k such that phi(k) = Sum_{d|k} core(d) where core(x) is the squarefree part of x (A007913).at n=20A074786Numbers n such that sigma(n) = 7*phi(n).at n=14A136540