n | a(n) |
---|---|
0 | 1 |
1 | 0 |
2 | 0 |
3 | 0 |
4 | 24 |
5 | 240 |
6 | 1560 |
7 | 8400 |
8 | 60984 |
9 | 912240 |
10 | 15938520 |
11 | 242998800 |
12 | 3300493944 |
13 | 44583979440 |
14 | 690641504280 |
15 | 12868117189200 |
16 | 264164524958904 |
17 | 5481631005177840 |
18 | 112822632387018840 |
19 | 2367468210865875600 |
20 | 52624238539033647864 |
21 | 1258531092544541563440 |
[1,0,0,0,24,240,1560,8400,60984,912240,15938520, 242998800,3300493944,44583979440,690641504280, 12868117189200,264164524958904,5481631005177840, 112822632387018840,2367468210865875600, 52624238539033647864,1258531092544541563440] |