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
KEYWORD
nonn
AUTHOR
Vladeta Jovovic, Jun 06 2004
EXTENSIONS
Terms a(21) and beyond from Andrew Howroyd, Feb 02 2021
STATUS
approved