a(n) = n! * Sum_{k=0..n} k^(3 * (n-k)) / (n-k)!.

A358687

a(n) = n! * Sum_{k=0..n} k^(3 * (n-k)) / (n-k)!.

Terms

    a(0) =1a(1) =1a(2) =4a(3) =57a(4) =1444a(5) =61785a(6) =4050126a(7) =373648513a(8) =47101090744

External references