OFFSET
0,4
LINKS
Andrew Howroyd, Table of n, a(n) for n = 0..500
T. Fowler, I. Gessel, G. Labelle, P. Leroux, The specification of 2-trees, Adv. Appl. Math. 28 (2) (2002) 145-168, Table 1.
PROG
(PARI) C(30, 3) \\ See A340812 for C(n, k). - Andrew Howroyd, May 09 2021
CROSSREFS
KEYWORD
nonn
AUTHOR
R. J. Mathar, Apr 29 2018
EXTENSIONS
Name clarified by Andrew Howroyd, May 09 2021
STATUS
approved