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

A280797

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

Terms

    a(0) =0a(1) =0a(2) =5a(3) =182a(4) =13107a(5) =1627604a(6) =310968905a(7) =84777884106

External references