n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 3 |
3 | 13 |
4 | 72 |
5 | 500 |
6 | 4020 |
7 | 37380 |
8 | 389760 |
9 | 4546080 |
10 | 58363200 |
11 | 814968000 |
12 | 12301027200 |
13 | 200216016000 |
14 | 3484710028800 |
15 | 64639070496000 |
16 | 1270187702784000 |
17 | 26414731639296000 |
18 | 578733086131200000 |
19 | 13328586071184384000 |
20 | 321801976039864320000 |
21 | 8127599117746268160000 |
[1,1,3,13,72,500,4020,37380,389760,4546080, 58363200,814968000,12301027200,200216016000, 3484710028800,64639070496000,1270187702784000, 26414731639296000,578733086131200000, 13328586071184384000,321801976039864320000, 8127599117746268160000] |