n | a(n) |
---|---|
1 | 0 |
2 | 0 |
3 | 4 |
4 | 12 |
5 | 144 |
6 | 720 |
7 | 8640 |
8 | 60480 |
9 | 806400 |
10 | 7257600 |
11 | 108864000 |
12 | 1197504000 |
13 | 20118067200 |
14 | 261534873600 |
15 | 4881984307200 |
16 | 73229764608000 |
17 | 1506440871936000 |
18 | 25609494822912000 |
19 | 576213633515520000 |
20 | 10948059036794880000 |
21 | 267619220899430400000 |
22 | 5620003638888038400000 |
[0,0,4,12,144,720,8640,60480,806400,7257600, 108864000,1197504000,20118067200,261534873600, 4881984307200,73229764608000,1506440871936000, 25609494822912000,576213633515520000, 10948059036794880000,267619220899430400000, 5620003638888038400000] |