A104983-OEIS公司

A104983号作为一个简单的表

n个	a（n）
0	1
1	2
2	6
三	24
4	122
5	750
6	5376
7	43856
8	400518
9	4046334
10	44808104
11	539850984
12	7032370302
13	98516491214
14	1477264979352
15	23612920280976
16	400847064718166
17	7202901369491694
18	136596819590256984
19	2726503675380494408

[1,2,6,24,122,750,5376,43856,400518,4046334,44808104,539850984,7032370302,98516491214,1477264979352,23612920280976,400847064718166,7202901369491694,136596819590256984,2726503675380494408]