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

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A241543 a(n) = A241477(n, n). 4
1, 1, 2, 2, 2, 6, 4, 20, 10, 70, 28, 252, 84, 924, 264, 3432, 858, 12870, 2860, 48620, 9724, 184756, 33592, 705432, 117572, 2704156, 416024, 10400600, 1485800, 40116600, 5348880, 155117520, 19389690, 601080390, 70715340, 2333606220, 259289580, 9075135300 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,3
COMMENTS
See A241477 and A232500 for the combinatorial definitions.
LINKS
FORMULA
a(n) = 2*floor(n/2)*(n-2)!/floor(n/2)!^2 for n>=2.
a(n+2) = 2*A057977(n) for n>=0. - Peter Luschny, Jul 17 2016
MAPLE
A241543 := proc(n)
if n < 2 then 1
else 2*iquo(n, 2)*(n-2)!/iquo(n, 2)!^2
fi end:
seq(A241543(n), n=0..37);
CROSSREFS
Sequence in context: A324339 A211391 A309078 * A210740 A209820 A145890
KEYWORD
nonn
AUTHOR
Peter Luschny, Apr 25 2014
STATUS
approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 18 06:24 EDT 2024. Contains 371769 sequences. (Running on oeis4.)