|
| |
|
|
A128087
|
|
Sum of squared coefficients of q in the q-analog of the even double factorials.
|
|
2
| |
|
|
1, 2, 14, 296, 12938, 956720, 107245250, 16966970200, 3601980861720, 988252809411908, 340375635448973106, 143798619953044471444, 73123320014581106403732, 44060303354020797873285800
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,2
|
|
|
COMMENTS
| See A128083 for sum of squared coefficients of q in the q-analog of the odd double factorials. Also, A127728 is the sum of squared coefficients of q in the q-factorials.
|
|
|
PROG
| (PARI) {a(n)=if(n==0, 1, sum(k=0, n^2, polcoeff(prod(j=1, n, (1-q^(2*j))/(1-q)), k, q)^2))}
|
|
|
CROSSREFS
| Cf. A000165 ((2n)!!); A128084 (triangle), A128085 (central terms), A128086 (diagonal); A127728.
Sequence in context: A018803 A132695 A015015 * A139225 A078675 A165696
Adjacent sequences: A128084 A128085 A128086 * A128088 A128089 A128090
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| Paul D. Hanna (pauldhanna(AT)juno.com), Feb 14 2007
|
| |
|
|
