a(n) = 8*(6*n^2-37*n+60)*n^(n-7)*(2*n-7)!/(n-4)!.

A134164

a(n) = 8*(6*n^2-37*n+60)*n^(n-7)*(2*n-7)!/(n-4)!.

Terms

    a(0) =1a(1) =48a(2) =4320a(3) =638400a(4) =143216640a(5) =45912303360

External references