a(n) = n! * d(n), where n! = factorial numbers (A000142), d(n) = subfactorial numbers (A000166).

A082491

a(n) = n! * d(n), where n! = factorial numbers (A000142), d(n) = subfactorial numbers (A000166).

Terms

    a(0) =1a(1) =0a(2) =2a(3) =12a(4) =216a(5) =5280a(6) =190800a(7) =9344160a(8) =598066560a(9) =48443028480

External references