A026080-OEIS公司

A026080型作为一个简单的表

n个	a（n）
0	1
1	2
2	4
三	7
4	22
5	64
6	191
7	567
8	1689
9	5033
10	15013
11	44809
12	133816
13	399802
14	1194949
15	3572693
16	10684758
17	31962456
18	95633229
19	286193409
20	856610214
21	2564317356
22	7677475521
23	22988860305
24	68843627049
25	206183053485
26	617563017927
27	1849887488987

[1,2,4,7,22,64,191,567,1689,5033,15013,44809,133816,399802,1194949,3572693,10684758,31962456,95633229,286193409,856610214,2564317356,7677475521,22988860305,68843627049,206183053485,617563017927,1849887488987]