A174318 a(n) = ceiling(n!/e) with e = A001113 = exp(1).

1, 1, 1, 3, 9, 45, 265, 1855, 14833, 133497, 1334961, 14684571, 176214841, 2290792933, 32071101049, 481066515735, 7697064251745, 130850092279665, 2355301661033953, 44750731559645107, 895014631192902121, 18795307255050944541, 413496759611120779881

Offset

0,4

References

F. S. Roberts, Applied Combinatorics, Prentice-Hall, 1984, p. 263.

Links

Table of n, a(n) for n=0..22.

Formula

a(2n) = A000166(2n). a(2n+1) = A000166(2n+1)+1.

Mathematica

Table[Ceiling[n!*Exp[ -1]], {n, 0, 30}]

Prog

(PARI) a(n) = ceil(n!/exp(1)); \\ Michel Marcus, May 15 2017

Crossrefs

Cf. A000166.

Sequence in context: A328267 A038059 A369388 * A338575 A004990 A027616

Adjacent sequences: A174315 A174316 A174317 * A174319 A174320 A174321

Keyword

nonn

Author

Roger L. Bagula, Mar 15 2010

Status

approved