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

A330260

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

Terms

    a(0) =1a(1) =2a(2) =17a(3) =352a(4) =13505a(5) =830126a(6) =74717857a(7) =9263893892

External references