A239453 - OEIS

%I #9 Mar 15 2020 05:06:31

%S 1,2,3,8,11,30,43,112,172,420,694,1584,2809,6006,11379,22880,46088,

%T 87516,186562,335920,754646,1293292,3050238,4992288,12319816,19315400,

%U 49725004,74884320,200571541,290845350,808559299,1131445440,3257808976,4407922860,13119940234

%N Convolution of the generalized Catalan numbers A057977 with themselves.

%o (Sage)

%o def A239453_list(n):

%o     r = sqrt(1-4*x^2)

%o     g = lambda x: (1-r)*(r+x)/(2*x^2*r)

%o     s = taylor(g(x), x, 0, n+1)

%o     f = [s.coefficient(x, j) for j in (0..n+1)]

%o     return [add(f[k]*f[j-k] for k in (0..j)) for j in (0..n)]

%o A239453_list(36)

%Y Cf. A162551.

%K nonn

%O 0,2

%A _Peter Luschny_, Mar 19 2014