A234596 - OEIS

A234596

Bicolored noncrossing configurations.

1, 8, 80, 992, 13760, 204416, 3180800, 51176960, 844467200, 14212646912, 243034542080, 4210466545664, 73745071063040, 1303643374125056, 23229596506849280, 416799595720736768, 7523942192296755200, 136549608206371389440, 2490043714311736524800, 45601540046865462984704

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OFFSET

1,2

LINKS

Table of n, a(n) for n=1..20.

F. Chapoton, S. Giraudo, Enveloping operads and bicoloured noncrossing configurations, arXiv preprint arXiv:1310.4521 [math.CO], 2013. See Prop. 2.9.

Samuele Giraudo, Combalgebraic structures on decorated cliques, Formal Power Series and Algebraic Combinatorics, Séminaire Lotharingien de Combinatoire, 78B.15, 2017, p. 8; arXiv:1709.08416 [math.CO], 2017.

FORMULA

For a g.f. see F. Chapoton, S. Giraudo (2013), Prop. 2.9.

G.f.: 1/6*(1-4*t-sqrt(1-20*t+4*t^2)). - Paul Laubie, Nov 08 2023

PROG

(Sage) R.<t>=PowerSeriesRing(QQ); (1/6*(1-4*t-sqrt(1-20*t+4*t^2))).list()[1:]

CROSSREFS

Sequence in context: A053175 A051580 A228658 * A060375 A097815 A002718

Adjacent sequences: A234593 A234594 A234595 * A234597 A234598 A234599

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Jan 04 2014

EXTENSIONS

More terms from Paul Laubie, Nov 08 2023

STATUS

approved