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A024485 a(n) = (2/(3n-1))*C(3n,n). 0
-2, 3, 6, 21, 90, 429, 2184, 11628, 63954, 360525, 2072070, 12096045, 71524440, 427496076, 2578547760, 15675792072, 95951017602, 590842763469, 3657598059570, 22749427475775, 142096423925610 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

LINKS

Table of n, a(n) for n=0..20.

FORMULA

G.f.: 3*g-2 where g*(1-g)^2 = x. - Mark van Hoeij, Nov 09 2011

MAPLE

[seq((2/(3*n-1))*binomial(3*n, n), n=0..40)];

MATHEMATICA

Table[2/(3n-1) Binomial[3n, n], {n, 0, 20}] (* Harvey P. Dale, Nov 21 2015 *)

CROSSREFS

Sequence in context: A025239 A127294 A012924 * A013155 A007501 A227367

Adjacent sequences:  A024482 A024483 A024484 * A024486 A024487 A024488

KEYWORD

sign

AUTHOR

Clark Kimberling

STATUS

approved

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Last modified December 5 07:11 EST 2016. Contains 278761 sequences.