A264687-组织环境信息系统

A264687型作为一个简单的表

n个	a（n）
0	0
1	1
2	1
三	2
4	2
5	5
6	4
7	11
8	10
9	22
10	22
11	50
12	43
13	104
14	100
15	209
16	206
17	446
18	418
19	914
20	886
21	1838
22	1825
23	3800
24	3664
25	7696
26	7591
27	15470
28	15370
29	31466
30	30910
31	63398
32	62866
33	127154
34	126742
35	256559
36	254156
37	515168
38	513004
39	1032104
40	1029997
41	2073626
42	2063866
43	4156118

[0,1,1,2,2,5,4,11,10,22,22,50,43,104,100,209,206,446,418,914,886,1838,1825,3800,3664,7696,7591,15470,15370,31466,30910,63398,62866,127154,126742,256559,254156,515168,513004,1032104,1029997,2073626,2063866,4156118]