n | a(n) |
---|---|
1 | 1 |
2 | 0 |
3 | 0 |
4 | 0 |
5 | 10 |
6 | 60 |
7 | 462 |
8 | 3920 |
9 | 36954 |
10 | 382740 |
11 | 4327510 |
12 | 53088888 |
13 | 702756210 |
14 | 9988248956 |
15 | 151751644590 |
16 | 2454798429600 |
17 | 42130249479562 |
18 | 764681923900260 |
19 | 14636063499474054 |
20 | 294639009867223880 |
[1,0,0,0,10,60,462,3920,36954,382740,4327510, 53088888,702756210,9988248956,151751644590, 2454798429600,42130249479562,764681923900260, 14636063499474054,294639009867223880] |