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

 

Logo

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 56th year, we are closing in on 350,000 sequences, and we’ve crossed 9,700 citations (which often say “discovered thanks to the OEIS”).

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A055579 a(n) = binomial(12*n-1,3*n-1)/((6*n-1)*(12*n-1)). 0
1, 133, 39556, 16112057, 7772368380, 4168218286276, 2403705165816240, 1461462393790971585, 925088518413937893358, 604420266372219374357644, 405139322689963395796890100, 277349882927724253636179972980 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..12.

C. O. Oakley and R. J. Wisner, Flexagons, Amer. Math. Monthly 64 (1957), 143-154, see p. 151.

MATHEMATICA

Table[Binomial[12n-1, 3n-1]/((6n-1)(12n-1)), {n, 20}] (* Harvey P. Dale, Nov 02 2011 *)

PROG

(PARI) a(n) = binomial(12*n-1, 3*n-1)/((6*n-1)*(12*n-1)); \\ Michel Marcus, Sep 29 2017

CROSSREFS

Sequence in context: A129049 A281496 A015264 * A191715 A208626 A061491

Adjacent sequences:  A055576 A055577 A055578 * A055580 A055581 A055582

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Aug 24 2000

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 December 4 02:40 EST 2021. Contains 349469 sequences. (Running on oeis4.)