A319672 - cp's OEIS frontend

A319672 a(n) = [x^n] Product_{k>=2} ((1 + x^k)/(1 - x^k))^n.

n	a(n)
0	1
1	0
2	4
3	6
4	40
5	110
6	520
7	1778
8	7568
9	28320
10	116224
11	453046
12	1837600
13	7306234
14	29565848
15	118786526
16	481192480
17	1945153838
18	7895908852
19	32046260282
20	130370798320
21	530650047710
22	2163191769336
23	8824509524082
24	36037768384832
25	147277910160160
26	602398740105712
27	2465582764631334

[1, 0, 4, 6, 40, 110, 520, 1778, 7568, 28320, 116224, 453046, 1837600, 7306234, 29565848, 118786526, 481192480, 1945153838, 7895908852, 32046260282, 130370798320, 530650047710, 2163191769336, 8824509524082, 36037768384832, 147277910160160, 602398740105712, 2465582764631334]

cp's OEIS Frontend

A319672 a(n) = [x^n] Product_{k>=2} ((1 + x^k)/(1 - x^k))^n.

Table of values

List of values