OFFSET
0,5
FORMULA
G.f. y(x) satisfies x y^4 + 2 x^2 y^2 + x^3 + 3 x y^2 + y^3 - x y = 0.
PROG
(Sage)
N = 30
x = (PowerSeriesRing(QQ, 'x').0).O(N + 1)
f = (x*(1-x^2)^2/(1+x^3)^2).reverse()
g = sum(catalan_number(n)*x**n for n in range(N + 1)).O(N + 1)
list(x*g-f)
CROSSREFS
KEYWORD
nonn
AUTHOR
F. Chapoton, Jul 14 2021
STATUS
approved