n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 1 |
3 | 3 |
4 | 8 |
5 | 40 |
6 | 180 |
7 | 140 |
8 | 896 |
9 | 72576 |
10 | 604800 |
11 | 6652800 |
12 | 68428800 |
13 | 59304960 |
14 | 726485760 |
15 | 163459296000 |
16 | 2324754432000 |
17 | 39520825344000 |
18 | 640237370572800 |
19 | 579262382899200 |
20 | 10532043325440000 |
21 | 4644631106519040000 |
[1,1,1,3,8,40,180,140,896,72576,604800,6652800, 68428800,59304960,726485760,163459296000, 2324754432000,39520825344000,640237370572800, 579262382899200,10532043325440000, 4644631106519040000] |