a(n) = exp(-1) * Sum_{k>=0} (k + n - 1)!^n/(k!*(k - 1)!^n).

A308537

a(n) = exp(-1) * Sum_{k>=0} (k + n - 1)!^n/(k!*(k - 1)!^n).

Terms

    a(0) =1a(1) =1a(2) =27a(3) =104149a(4) =192052025697

External references