n | a(n) |
---|---|
0 | 0 |
1 | 2 |
2 | 48 |
3 | 578 |
4 | 4672 |
5 | 28610 |
6 | 142000 |
7 | 596610 |
8 | 2187520 |
9 | 7159170 |
10 | 21278640 |
11 | 58227906 |
12 | 148321344 |
13 | 354870594 |
14 | 803467056 |
15 | 1732242690 |
16 | 3575055360 |
17 | 7094825730 |
18 | 13591279920 |
19 | 25216532290 |
20 | 45443741760 |
21 | 79749022402 |
[0,2,48,578,4672,28610,142000,596610,2187520, 7159170,21278640,58227906,148321344,354870594, 803467056,1732242690,3575055360,7094825730, 13591279920,25216532290,45443741760,79749022402] |