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

A281596

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

Terms

    a(0) =0a(1) =0a(2) =1a(3) =6a(4) =55a(5) =660a(6) =9751a(7) =170898a(8) =3463615a(9) =79669320a(10) =2050086511a(11) =58346365110

External references