A207397 - cp's OEIS frontend

A207397 G.f.: Sum_{n>=0} Product_{k=1..n} (q^k - 1) where q = (1+x)/(1+x^2).

n	a(n)
0	1
1	1
2	1
3	2
4	11
5	74
6	557
7	4799
8	47004
9	516717
10	6302993
11	84502346
12	1235198136
13	19552296646
14	333212892221
15	6083009119262
16	118433569748072
17	2449663066933397
18	53643715882853914
19	1239875630317731463
20	30163779836127304106
21	770476745704778418686

[1, 1, 1, 2, 11, 74, 557, 4799, 47004, 516717, 6302993, 84502346, 1235198136, 19552296646, 333212892221, 6083009119262, 118433569748072, 2449663066933397, 53643715882853914, 1239875630317731463, 30163779836127304106, 770476745704778418686]

cp's OEIS Frontend

A207397 G.f.: Sum_{n>=0} Product_{k=1..n} (q^k - 1) where q = (1+x)/(1+x^2).

Table of values

List of values