n | a(n) |
---|---|
1 | 1 |
2 | 0 |
3 | 1 |
4 | 3 |
5 | 20 |
6 | 60 |
7 | 630 |
8 | 2688 |
9 | 27913 |
10 | 201600 |
11 | 3326400 |
12 | 17107200 |
13 | 444787200 |
14 | 3632428800 |
15 | 54486432000 |
16 | 674928706064 |
17 | 19760412672000 |
18 | 164163428352000 |
19 | 6082255020441600 |
20 | 57926238289920000 |
21 | 1596591942865920000 |
22 | 31222242438266880000 |
23 | 1077167364120207360000 |
24 | 10340806695553990656000 |
[1,0,1,3,20,60,630,2688,27913,201600,3326400, 17107200,444787200,3632428800,54486432000, 674928706064,19760412672000,164163428352000, 6082255020441600,57926238289920000, 1596591942865920000,31222242438266880000, 1077167364120207360000,10340806695553990656000] |