A104987-OEIS公司

A104987号作为一个简单的表

n个	a（n）
0	0
1	1
2	4
三	14
4	58
5	300
6	1886
7	13878
8	116310
9	1090500
10	11296810
11	128102714
12	1578342010
13	20998804576
14	300081098918
15	4584908039142
16	74594230462318
17	1287634918033836
18	23506502407089874
19	452508152936326482

[0,1,4,14,58,300,1886,13878,116310,1090500,11296810,128102714,1578342010,20998804576,300081098918,4584908039142,74594230462318,1287634918033836,23506502407089874,452508152936326482]