392400domain: NAppears in sequencesCoefficient of X^2 in expansion of (1 + n*X + n*X^2)^n.at n=29A092365Coreful triperfect numbers: numbers k such that csigma(k) = 3*k, where csigma(k) is the sum of the coreful divisors of k (A057723).at n=32A364990