A227681 - cp's OEIS frontend

A227681 G.f.: exp( Sum_{n>=1} x^n * (1+x)^n / (n*(1-x^n)) ).

n	a(n)
0	1
1	1
2	3
3	6
4	12
5	23
6	43
7	79
8	142
9	252
10	442
11	766
12	1316
13	2244
14	3799
15	6393
16	10704
17	17841
18	29618
19	49000
20	80823
21	132964
22	218242
23	357501
24	584608
25	954553
26	1556575
27	2535425
28	4125805
29	6708143
30	10898897
31	17696749
32	28719276
33	46586050
34	75538702
35	122444483
36	198420445
37	321461918

[1, 1, 3, 6, 12, 23, 43, 79, 142, 252, 442, 766, 1316, 2244, 3799, 6393, 10704, 17841, 29618, 49000, 80823, 132964, 218242, 357501, 584608, 954553, 1556575, 2535425, 4125805, 6708143, 10898897, 17696749, 28719276, 46586050, 75538702, 122444483, 198420445, 321461918]

cp's OEIS Frontend

A227681 G.f.: exp( Sum_{n>=1} x^n * (1+x)^n / (n*(1-x^n)) ).

Table of values

List of values