a(n) = n! * Sum_{k=1..n-1} (-1)^(k+1) * n^(n-k-2) / (n-k-1)!.
A347994
a(n) = n! * Sum_{k=1..n-1} (-1)^(k+1) * n^(n-k-2) / (n-k-1)!.
Terms
- a(0) =0a(1) =1a(2) =4a(3) =30a(4) =296a(5) =3720a(6) =56652a(7) =1014832a(8) =20909520a(9) =487198080a(10) =12667470740a(11) =363607605504
External references
- oeis: A347994