A094656 - OEIS

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A094656

Number of unlabeled 12-gonal 2-trees with n 12-gons.

1, 1, 1, 7, 55, 840, 15189, 309607, 6671842, 149850849, 3471296793, 82442359291, 1998559329142, 49290785442796, 1233639304644946, 31268489727956101, 801335133177932829, 20736286803363051714, 541224489038545084067, 14234799536039481373552, 376974819516101224941091

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,4

LINKS

Andrew Howroyd, Table of n, a(n) for n = 0..200

G. Labelle, C. Lamathe and P. Leroux, Labeled and unlabeled enumeration of k-gonal 2-trees, arXiv:math/0312424 [math.CO], Dec 23 2003.

CROSSREFS

Column k=12 of A340811.

Cf. A054581.

Sequence in context: A365030 A180829 A227544 * A239156 A117993 A055056

Adjacent sequences: A094653 A094654 A094655 * A094657 A094658 A094659

KEYWORD

nonn

AUTHOR

Vladeta Jovovic, Jun 06 2004

EXTENSIONS

Terms a(19) and beyond from Andrew Howroyd, Feb 02 2021

STATUS

approved