A117125 - OEIS

The OEIS is supported by the many generous donors to the OEIS Foundation.

A117125

Positive integers that can be expressed as the difference between a factorial and a double factorial.

0

0, 1, 3, 4, 5, 9, 15, 16, 21, 22, 23, 72, 105, 112, 117, 118, 119, 336, 615, 672, 705, 712, 717, 718, 719, 1200, 4095, 4656, 4935, 4992, 5025, 5032, 5037, 5038, 5039

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,3

LINKS

Table of n, a(n) for n=1..35.

FORMULA

n! - m!! being n! > m!!

EXAMPLE

117 = 5! - 3!!

4992 = 7! - 6!!

CROSSREFS

Cf. A110903, A111300.

Sequence in context: A356604 A050161 A195609 * A000692 A195971 A080552

Adjacent sequences: A117122 A117123 A117124 * A117126 A117127 A117128

KEYWORD

nonn

AUTHOR

Paolo P. Lava and Giorgio Balzarotti, Apr 20 2006

STATUS

approved