2076867domain: NAppears in sequencesNumbers k such that sigma(k^2) and Sum_{d|k} d*sigma(d) are both multiples of k.at n=8A232067Numbers k that divide sigma(k^2) where sigma is the sum of divisors function (A000203).at n=15A232354Numbers n such that n = gcd(n^2, sigma(n^2)).at n=6A247222