n | a(n) |
---|---|
2 | 1 |
3 | 1 |
4 | 12 |
5 | 4 |
6 | 360 |
7 | 40 |
8 | 20160 |
9 | 12096 |
10 | 259200 |
11 | 604800 |
12 | 239500800 |
13 | 760320 |
14 | 43589145600 |
15 | 217945728000 |
16 | 1494484992000 |
17 | 697426329600 |
18 | 3201186852864000 |
19 | 16937496576000 |
20 | 1216451004088320000 |
21 | 30964207376793600 |
22 | 11469395181404160000 |
[1,1,12,4,360,40,20160,12096,259200,604800, 239500800,760320,43589145600,217945728000, 1494484992000,697426329600,3201186852864000, 16937496576000,1216451004088320000, 30964207376793600,11469395181404160000] |