A181179 a(1)=1; for n>=2, a(n) = 2*a(n-1)!.

1, 2, 4, 48, 24827831185072145341724578094746750077042972709355520000000000

Offset

1,2

Links

Table of n, a(n) for n=1..5.

Mathematica

NestList[2#!&, 1, 4] (* Harvey P. Dale, Aug 29 2015 *)

Crossrefs

Sequence in context: A097424 A228596 A032019 * A175814 A303382 A303443

Adjacent sequences: A181176 A181177 A181178 * A181180 A181181 A181182

Keyword

nonn

Author

H Gee (harry987(AT)live.com.au), Oct 08 2010

Extensions

Corrected by Harvey P. Dale, Aug 29 2015

Definition changed by Georg Fischer, Jun 16 2021

Status

approved