n | a(n) |
---|---|
0 | 0 |
1 | 0 |
2 | 0 |
3 | 6 |
4 | 12 |
5 | 40 |
6 | 180 |
7 | 1008 |
8 | 6720 |
9 | 51840 |
10 | 453600 |
11 | 4435200 |
12 | 47900160 |
13 | 566092800 |
14 | 7264857600 |
15 | 100590336000 |
16 | 1494484992000 |
17 | 23712495206400 |
18 | 400148356608000 |
19 | 7155594141696000 |
20 | 135161222676480000 |
21 | 2688996956405760000 |
22 | 56200036388880384000 |
23 | 1231048416137379840000 |
[0,0,0,6,12,40,180,1008,6720,51840,453600,4435200, 47900160,566092800,7264857600,100590336000, 1494484992000,23712495206400,400148356608000, 7155594141696000,135161222676480000, 2688996956405760000,56200036388880384000, 1231048416137379840000] |