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%I #10 Mar 19 2016 06:31:35
%S 1,2,9,64,624,7736,116416,2060808,41952600,965497440,24786054816,
%T 702201877920,21761251764672,732269872931712,26589359234860560,
%U 1036241806935453696,43142510740036313088,1911022260200150482944,89737455913330610995200,4452805047268938247981056,232806644343118618035904512,12791828071344703747110764544,736928909474399720669590216704,44416721474748725213260027514880
%N Self-convolution of A128318.
%C A128318 equals row 0 of table A128570.
%H Paul D. Hanna, <a href="/A128577/b128577.txt">Table of n, a(n) for n = 0..200</a>
%F G.f.: A(x) = [1 + x*R(x,1)^2]^2, where R(x,1) = 1 + 2*x*R(x,2)^2, R(x,2) = 1 + 3*x*R(x,3)^2, ..., R(x,n) = 1 + (n+1)*x*R(x,n+1)^2, ... and R(x,n) is the g.f. of row n of table A128570.
%F a(n) ~ 2*A128318(n). - _Vaclav Kotesovec_, Mar 19 2016
%o (PARI) {a(n)=local(A=1+(n+1)*x);for(j=0,n,A=1+(n+1-j)*x*A^2 +x*O(x^n)); polcoeff(A^2,n)}
%o for(n=0, 25, print1(a(n), ", "))
%Y Cf. A128570 (triangle), rows: A128318, A128571, A128572, A128573, A128574, A128575, A128576; A128578 (main diagonal), A128579 (antidiagonal sums).
%K nonn
%O 0,2
%A _Paul D. Hanna_, Mar 11 2007
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