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A239453
Convolution of the generalized Catalan numbers A057977 with themselves.
0
1, 2, 3, 8, 11, 30, 43, 112, 172, 420, 694, 1584, 2809, 6006, 11379, 22880, 46088, 87516, 186562, 335920, 754646, 1293292, 3050238, 4992288, 12319816, 19315400, 49725004, 74884320, 200571541, 290845350, 808559299, 1131445440, 3257808976, 4407922860, 13119940234
OFFSET
0,2
PROG
(Sage)
def A239453_list(n):
r = sqrt(1-4*x^2)
g = lambda x: (1-r)*(r+x)/(2*x^2*r)
s = taylor(g(x), x, 0, n+1)
f = [s.coefficient(x, j) for j in (0..n+1)]
return [add(f[k]*f[j-k] for k in (0..j)) for j in (0..n)]
A239453_list(36)
CROSSREFS
Cf. A162551.
Sequence in context: A285113 A335632 A048788 * A143914 A041123 A042045
KEYWORD
nonn
AUTHOR
Peter Luschny, Mar 19 2014
STATUS
approved