a(n) = n! * Sum_{d|n} d^n / (n/d)!.

A354892

a(n) = n! * Sum_{d|n} d^n / (n/d)!.

Terms

    a(0) =1a(1) =9a(2) =163a(3) =6337a(4) =375001a(5) =33862441a(6) =4150656721a(7) =677778984961

External references