A094652 Number of unlabeled octagonal 2-trees with n octagons.

1, 1, 1, 5, 26, 245, 2737, 35291, 483819, 6937913, 102666626, 1558022255, 24133790815, 380320794122, 6081804068869, 98490990290897, 1612634990857755, 26660840123167203, 444560998431678554, 7469779489114328514, 126375763235359105446, 2151342943131421629636

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=8 of A340811.

Cf. A054581.

Sequence in context: A305201 A099032 A277489 * A027529 A368294 A366700

Adjacent sequences: A094649 A094650 A094651 * A094653 A094654 A094655

Keyword

nonn

Author

Vladeta Jovovic, Jun 06 2004

Extensions

Terms a(20) and beyond from Andrew Howroyd, Feb 02 2021

Status

approved