A386706 - cp's OEIS frontend

A386706 Expansion of ((Product_{k>=1} (1 - x^k)^2/(1 - 4*x^k + x^(2k))) - 1)/2.

n	a(n)
0	0
1	1
2	5
3	18
4	71
5	260
6	990
7	3672
8	13775
9	51343
10	191860
11	715770
12	2672298
13	9972092
14	37220040
15	138903480
16	518408351
17	1934712530
18	7220497115
19	26947209762
20	100568547820
21	375326739216
22	1400739172470
23	5227629044040
24	19509779871450
25	72811487038701
26	271736178975820
27	1014133216234068

[0, 1, 5, 18, 71, 260, 990, 3672, 13775, 51343, 191860, 715770, 2672298, 9972092, 37220040, 138903480, 518408351, 1934712530, 7220497115, 26947209762, 100568547820, 375326739216, 1400739172470, 5227629044040, 19509779871450, 72811487038701, 271736178975820, 1014133216234068]

cp's OEIS Frontend

A386706 Expansion of ((Product_{k>=1} (1 - x^k)^2/(1 - 4*x^k + x^(2k))) - 1)/2.

Table of values

List of values