A207557 - cp's OEIS frontend

A207557 G.f.: Sum_{n>=0} 1/(1+x)^(n^2-n) * Product_{k=1..n} ((1+x)^(2*k-1) - 1).

n	a(n)
0	1
1	1
2	3
3	12
4	64
5	420
6	3276
7	29581
8	303389
9	3483053
10	44245695
11	616103046
12	9330961666
13	152700926414
14	2685132170466
15	50488787588936
16	1010864433071206
17	21470488933116138
18	482176661100286182
19	11415700804801064258
20	284169548252819022230
21	7419733139418740010570

[1, 1, 3, 12, 64, 420, 3276, 29581, 303389, 3483053, 44245695, 616103046, 9330961666, 152700926414, 2685132170466, 50488787588936, 1010864433071206, 21470488933116138, 482176661100286182, 11415700804801064258, 284169548252819022230, 7419733139418740010570]

cp's OEIS Frontend

A207557 G.f.: Sum_{n>=0} 1/(1+x)^(n^2-n) * Product_{k=1..n} ((1+x)^(2*k-1) - 1).

Table of values

List of values