n!*(9*n^4-78*n^3+235*n^2-438*n+680)/72.

A108034

n!*(9*n^4-78*n^3+235*n^2-438*n+680)/72.

Terms

    a(0) =0a(1) =400a(2) =13280a(3) =278880a(4) =5120640a(5) =90518400a(6) =1602720000a(7) =28966291200a(8) =539568691200

External references