n | a(n) |
---|---|
2 | 0 |
3 | 2 |
4 | 2 |
5 | 6 |
6 | 34 |
7 | 132 |
8 | 448 |
9 | 1986 |
10 | 8422 |
11 | 39902 |
12 | 195946 |
13 | 1024366 |
14 | 5505428 |
15 | 31185644 |
16 | 183904498 |
17 | 1119250852 |
18 | 7025176096 |
19 | 45663175776 |
20 | 306194071810 |
21 | 2107066845486 |
22 | 14874884490258 |
23 | 107949634637898 |
[0,2,2,6,34,132,448,1986,8422,39902,195946, 1024366,5505428,31185644,183904498,1119250852, 7025176096,45663175776,306194071810,2107066845486, 14874884490258,107949634637898] |