a(n) = A000407(n) - A086984(n).

A086985

a(n) = A000407(n) - A086984(n).

Terms

    a(0) =0a(1) =0a(2) =0a(3) =144a(4) =6000a(5) =198000a(6) =6420960a(7) =218453760a(8) =7988440320a(9) =316674489600

External references