A102231 Column 1 of triangle A102230 and equals the convolution of A032349 with A032349 shift right.

0, 1, 5, 32, 236, 1896, 16116, 142544, 1298524, 12100952, 114820964, 1105574400, 10775285836, 106098789832, 1053858546516, 10546951101360, 106249238782652, 1076554249491640, 10964085715303620, 112175072002688480

Offset: 0

Author

Paul D. Hanna, Jan 01 2005

Keywords

• nonn

Crossrefs

Cf. A032349, A102230.

Programs

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))}