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Column 1 of triangle A102230 and equals the convolution of A032349 with A032349 shift right.
1

%I #4 Mar 30 2012 18:36:44

%S 0,1,5,32,236,1896,16116,142544,1298524,12100952,114820964,1105574400,

%T 10775285836,106098789832,1053858546516,10546951101360,

%U 106249238782652,1076554249491640,10964085715303620,112175072002688480

%N Column 1 of triangle A102230 and equals the convolution of A032349 with A032349 shift right.

%o (PARI) {a(n)=local(B=vector(n+1,k,if(k==1,1, sum(i=0,k-2,2^(i+1)*binomial(2*k-2,i)*binomial(k-1,i+1))/(k-1)))); return(polcoeff(Ser(B)^2+x*Ser(B)^4+x*O(x^n),n))}

%Y Cf. A032349, A102230.

%K nonn

%O 0,3

%A _Paul D. Hanna_, Jan 01 2005