1218361domain: NAppears in sequencesStarting positions of strings of five 4's in the decimal expansion of Pi.at n=5A083617Numbers n such that sigma(n) - n = Sum_{k|n, k < n} sigma*(k), where sigma(n) is the sum of the divisors of n and sigma*(k) is the sum of the anti-divisors of k.at n=30A259536