a(n) = n^n * (n + 2 - (1/12) * (n^2-1)).

A080290

a(n) = n^n * (n + 2 - (1/12) * (n^2-1)).

Terms

    a(0) =3a(1) =15a(2) =117a(3) =1216a(4) =15625a(5) =237168a(6) =4117715a(7) =79691776a(8) =1678822119a(9) =37500000000a(10) =855935011833

External references