login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A156986 a(n) = (n!!)!!. 0
1, 2, 3, 384, 2027025, 10409396852733332453861621760000 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..6.

FORMULA

a(n) = A006882(A006882(n)). - R. J. Mathar, Feb 22 2009

MAPLE

doublefactorial(doublefactorial(n)) ; # R. J. Mathar, Feb 22 2009

CROSSREFS

Cf. A006882.

Sequence in context: A065586 A110931 A097654 * A066849 A071219 A109855

Adjacent sequences:  A156983 A156984 A156985 * A156987 A156988 A156989

KEYWORD

nonn

AUTHOR

Aart Blokhuis (aartb(AT)win.tue.nl), Feb 20 2009

EXTENSIONS

Another term with fewer than 80 digits added by R. J. Mathar, Feb 22 2009

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 5 14:49 EDT 2021. Contains 343572 sequences. (Running on oeis4.)