72750domain: NAppears in sequencesa(n) = Sum_{k=1..n-1} k^3*sigma(k)*sigma(n-k).at n=9A000499Number of 5-leaf rooted trees with n levels.at n=23A007715Number of n X 3 1..3 arrays containing at least one of each value, all equal values connected, and rows considered as a single number in nondecreasing order.at n=8A166782