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

A369027

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

Terms

    a(0) =0a(1) =0a(2) =2a(3) =18a(4) =216a(5) =3200a(6) =56250a(7) =1143072a(8) =26353376a(9) =679477248a(10) =19371024450a(11) =605000000000

External references