711828domain: NAppears in sequencesPowerful numbers (A001694) which can be written as the sum of two relatively prime 3-powerful numbers (A036966) different from 1.at n=20A210470Powerful numbers of the form x^3 + y^3 with x and y coprime.at n=6A238120a(n) = Sum_{k=1..n^2, gcd(n,k) = 1} k.at n=38A308474