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

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