

A128087


Sum of squared coefficients of q in the qanalog of the even double factorials.


2



1, 2, 14, 296, 12938, 956720, 107245250, 16966970200, 3601980861720, 988252809411908, 340375635448973106, 143798619953044471444, 73123320014581106403732, 44060303354020797873285800
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OFFSET

0,2


COMMENTS

See A128083 for sum of squared coefficients of q in the qanalog of the odd double factorials. Also, A127728 is the sum of squared coefficients of q in the qfactorials.


LINKS

Table of n, a(n) for n=0..13.


PROG

(PARI) {a(n)=if(n==0, 1, sum(k=0, n^2, polcoeff(prod(j=1, n, (1q^(2*j))/(1q)), k, q)^2))}


CROSSREFS

Cf. A000165 ((2n)!!); A128084 (triangle), A128085 (central terms), A128086 (diagonal); A127728.
Sequence in context: A217474 A132695 A015015 * A139225 A277035 A078675
Adjacent sequences: A128084 A128085 A128086 * A128088 A128089 A128090


KEYWORD

nonn


AUTHOR

Paul D. Hanna, Feb 14 2007


STATUS

approved



