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

0,3

Links

Table of n, a(n) for n=0..19.

Prog

(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))}

Crossrefs

Cf. A032349, A102230.

Sequence in context: A243693 A364747 A053157 * A365181 A367281 A127089

Adjacent sequences: A102228 A102229 A102230 * A102232 A102233 A102234

Keyword

nonn

Author

Paul D. Hanna, Jan 01 2005

Status

approved