a(n) = n! * Sum_{d|n} (-1)^(d+1) * (n/d)^n / d!.
A363698
a(n) = n! * Sum_{d|n} (-1)^(d+1) * (n/d)^n / d!.
Terms
- a(0) =1a(1) =7a(2) =163a(3) =5951a(4) =375001a(5) =33337559a(6) =4150656721a(7) =675135713279
External references
- oeis: A363698
A363698
a(n) = n! * Sum_{d|n} (-1)^(d+1) * (n/d)^n / d!.