a(n) = n! * (!(n+1)) = n! * Sum_{k=0..n} k!.
A143217
a(n) = n! * (!(n+1)) = n! * Sum_{k=0..n} k!.
Terms
- a(0) =1a(1) =2a(2) =8a(3) =60a(4) =816a(5) =18480a(6) =629280a(7) =29806560a(8) =1864154880a(9) =148459288320
External references
- oeis: A143217
A143217
a(n) = n! * (!(n+1)) = n! * Sum_{k=0..n} k!.