A350268 - OEIS

A350268

a(n) = Sum_{k=0..n} (n - k)! * (n - 1)^k. Row sums of A350269.

1, 1, 4, 22, 168, 1720, 22670, 368784, 7134148, 159416704, 4027395330, 113235212800, 3501763366904, 118024658758656, 4303855119215782, 168777440194263040, 7081468496171815500, 316501174908316647424, 15010862087643791689322, 752916261526858377363456

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OFFSET

0,3

LINKS

Table of n, a(n) for n=0..19.

MATHEMATICA

a[1] = 1; a[n_] := Sum[(n - k)! * (n - 1)^k, {k, 0, n}]; Array[a, 20, 0] (* Amiram Eldar, Dec 25 2021 *)

PROG

(PARI) a(n) = sum(k=0, n, (n-k)!*(n-1)^k); \\ Michel Marcus, Dec 25 2021

CROSSREFS

Cf. A350269.

Sequence in context: A001827 A363115 A368285 * A353186 A346665 A340332

Adjacent sequences: A350265 A350266 A350267 * A350269 A350270 A350271

KEYWORD

nonn

AUTHOR

Peter Luschny, Dec 25 2021

STATUS

approved