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

A356673

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

Terms

    a(0) =1a(1) =1a(2) =3a(3) =31a(4) =901a(5) =45741a(6) =3960871a(7) =584698843a(8) =130554106761

External references