n | a(n) |
---|---|
0 | 1 |
1 | 2 |
2 | 4 |
3 | 20 |
4 | 56 |
5 | 336 |
6 | 1056 |
7 | 6864 |
8 | 22880 |
9 | 155584 |
10 | 537472 |
11 | 3762304 |
12 | 13312768 |
13 | 95091200 |
14 | 342328320 |
15 | 2481880320 |
16 | 9051563520 |
17 | 66378132480 |
[1,2,4,20,56,336,1056,6864,22880,155584,537472, 3762304,13312768,95091200,342328320,2481880320, 9051563520,66378132480] |