A129949 a(n) = n! - binomial(n,3).

1, 1, 2, 5, 20, 110, 700, 5005, 40264, 362796, 3628680, 39916635, 479001380, 6227020514, 87178290836, 1307674367545, 20922789887440, 355687428095320, 6402373705727184, 121645100408831031, 2432902008176638860, 51090942171709438670, 1124000727777607678460

Offset

0,3

Links

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

Mathematica

Table[n! - Binomial[n, 3], {n, 20}] (* David Callan, May 08 2016 *)

Crossrefs

Sequence in context: A201224 A305922 A019536 * A127065 A168357 A052850

Adjacent sequences: A129946 A129947 A129948 * A129950 A129951 A129952

Keyword

nonn,easy

Author

Roger L. Bagula, Jun 10 2007

Extensions

Edited by Joerg Arndt, Aug 03 2020

Status

approved