A094610 Number of unlabeled 4-gonal 2-trees with n 4-gons.

1, 1, 1, 3, 8, 32, 141, 749, 4304, 26492, 169263, 1115015, 7507211, 51466500, 358100288, 2523472751, 17978488711, 129325796854, 938234533024, 6858551493579, 50478955083341, 373815860588360, 2783730088637429, 20835514668765200, 156675846789962554, 1183195305751233833

Offset

0,4

Links

Andrew Howroyd, Table of n, a(n) for n = 0..500

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

Crossrefs

Column k=4 of A340811.

Cf. A054581.

Sequence in context: A151541 A022563 A103939 * A064316 A009438 A321520

Adjacent sequences: A094607 A094608 A094609 * A094611 A094612 A094613

Keyword

nonn

Author

Vladeta Jovovic, Jun 06 2004

Extensions

Terms a(21) and beyond from Andrew Howroyd, May 09 2021

Status

approved