n | a(n) |
---|---|
0 | 1 |
1 | 0 |
2 | 4 |
3 | 12 |
4 | 144 |
5 | 1200 |
6 | 15840 |
7 | 211680 |
8 | 3467520 |
9 | 61689600 |
10 | 1241049600 |
11 | 27223257600 |
12 | 654316185600 |
13 | 16999766784000 |
14 | 476167826534400 |
15 | 14282419447296000 |
16 | 457079267893248000 |
17 | 15539983733514240000 |
[1,0,4,12,144,1200,15840,211680,3467520,61689600, 1241049600,27223257600,654316185600, 16999766784000,476167826534400,14282419447296000, 457079267893248000,15539983733514240000] |