%I #3 Mar 30 2012 18:37:01
%S 1,2,5,15,53,217,1011,5260,30041,185677,1228209,8620874,63792445,
%T 495163451,4015888557,33923543492,297706713081,2708377382444,
%U 25495655264883,247952347547483,2487743315817023,25717746952124842
%N Row sums of triangle A125280, which is the convolution triangle of A030266.
%F G.f.: A(x) = (1/x)*G(x)/(1 - G(x)) where G(x) = x + x*G(G(x)) is g.f. of A030266.
%e A(x) = 1 + 2*x + 5*x^2 + 15*x^3 + 53*x^4 + 217*x^5 + 1011*x^6 +...
%e where 1 - 1/(1 + x*A(x)) = G(x) is the g.f. of A030266:
%e G(x) = x + x^2 + 2*x^3 + 6*x^4 + 23*x^5 + 104*x^6 + 531*x^7 + 2982*x^8+..
%o (PARI) {a(n)=local(G=x+x^2);for(i=0,n,G=x+x*subst(G,x,G+x^2*O(x^n))); polcoeff((-1+1/(1-G))/x,n,x)}
%Y Cf. A125280, A030266.
%K nonn
%O 0,2
%A _Paul D. Hanna_, Nov 26 2006