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A094637 Number of unlabeled hexagonal 2-trees with n hexagons. 0
1, 1, 1, 4, 16, 103, 799, 7286, 71094, 729974, 7743818, 84307887, 937002302, 10595117272, 121568251909, 1412555701804, 16594126114458, 196829590326284, 2354703777373055, 28385225424840078, 344524656398655124 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

LINKS

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

G. Labelle, C. Lamathe and P. Leroux, Labeled and unlabeled enumeration of k-gonal 2-trees

CROSSREFS

Cf. A054581.

Sequence in context: A074187 A111883 A245155 * A203716 A136793 A274889

Adjacent sequences:  A094634 A094635 A094636 * A094638 A094639 A094640

KEYWORD

nonn

AUTHOR

Vladeta Jovovic, Jun 06 2004

STATUS

approved

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Last modified February 23 11:33 EST 2018. Contains 299579 sequences. (Running on oeis4.)