A047090-OEIS公司

A047090型作为一个简单的表

n个	a（n）
0	1
1	2
2	三
三	6
4	12
5	21
6	42
7	84
8	155
9	310
10	620
11	1176
12	2352
13	4704
14	9071
15	18142
16	36284
17	70717
18	141434
19	282868
20	555268
21	1110536
22	2221072
23	4381656
24	8763312
25	17526624
26	34697879
27	69395758
28	138791516
29	275467455
30	550934910
31	1101869820
32	2191008499

[1,2,3,6,12,21,42,84,155,310,620,1176,2352,4704,9071,18142,36284,70717,141434,282868,555268,1110536,2221072,4381656,8763312,17526624,34697879,69395758,138791516,275467455,550934910,1101869820,2191008499]