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A065424 Catalan-like formula: a(n) = binomial(6m, 3m+1)/(9m+6). 1
1, 33, 1326, 59432, 2851425, 143291610, 7446255180, 396893583792, 21579377870484, 1192183281903845, 66734212415276406, 3776778437640143208, 215744630060724034270, 12423227699242323077940 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..100

FORMULA

G.f.: A*sqrt((A+1)*(1+9*A)) where A=x*(1+9*A)^3*(1+A). - Mark van Hoeij, Nov 16 2011

-(n-1)*(3*n+2)*(3*n+1)*a(n) + 8*(6*n-5)*(6*n-1)*(2*n-1)*a(n-1) = 0. - R. J. Mathar, Oct 31 2015

PROG

(MAGMA) [Binomial(6*n, 3*n+1)/(9*n+6): n in [1..20]]; // Vincenzo Librandi, Nov 17 2011

CROSSREFS

Cf. A000108, A065097.

Sequence in context: A158688 A294436 A242492 * A071268 A012805 A093756

Adjacent sequences:  A065421 A065422 A065423 * A065425 A065426 A065427

KEYWORD

nonn,easy

AUTHOR

Len Smiley, Nov 16 2001

STATUS

approved

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Last modified July 16 09:13 EDT 2020. Contains 335784 sequences. (Running on oeis4.)