n | a(n) |
---|---|
1 | 0 |
2 | 1 |
3 | 4 |
4 | 24 |
5 | 144 |
6 | 1080 |
7 | 8640 |
8 | 80640 |
9 | 806400 |
10 | 9072000 |
11 | 108864000 |
12 | 1437004800 |
13 | 20118067200 |
14 | 305124019200 |
15 | 4881984307200 |
16 | 83691159552000 |
17 | 1506440871936000 |
18 | 28810681675776000 |
19 | 576213633515520000 |
20 | 12164510040883200000 |
21 | 267619220899430400000 |
22 | 6182004002776842240000 |
[0,1,4,24,144,1080,8640,80640,806400,9072000, 108864000,1437004800,20118067200,305124019200, 4881984307200,83691159552000,1506440871936000, 28810681675776000,576213633515520000, 12164510040883200000,267619220899430400000, 6182004002776842240000] |