G.f. satisfies: A(x) = G(x/A(x)^2) and G(x) = A(x*G(x)^2) = Sum_{n>=0} C(2n,n)*C(2n+2,n+1)/(n+2)*x^n is the g.f. of A172392.
1, 4, 2, 8, 20, 96, 324, 1648, 6348, 33200, 137848, 732640, 3193296
1 seqfan posts
Mon Mar 29 23:06:44 CEST 2010 [seqfan] Re: Zeros in A172390 and A172391