80823domain: NAppears in sequencesG.f.: exp( Sum_{n>=1} x^n * (1+x)^n / (n*(1-x^n)) ).at n=20A227681a(n) = Sum_{k=1..n} tau(gcd(k,n)^gcd(k,n)), where tau(n) is the number of divisors of n.at n=41A344224Number of partitions of n where there are k^2 - 1 kinds of parts k.at n=14A363601