OFFSET
1,2
LINKS
Sean A. Irvine, Table of n, a(n) for n = 1..500
M. Bousquet-Mélou and J.-M. Fédou, The generating function of convex polyominoes: the resolution of a q-differential system, Discrete Math. 137 (1995) 53-75.
Sergi Elizalde, Symmetric peaks and symmetric valleys in Dyck paths, arXiv:2008.05669 [math.CO], 2020.
CROSSREFS
KEYWORD
nonn
AUTHOR
Steven Finch, Feb 04 2002
EXTENSIONS
More terms from Sean A. Irvine, Jan 02 2024
STATUS
approved