n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 6 |
3 | 30 |
4 | 143 |
5 | 660 |
6 | 3000 |
7 | 13448 |
8 | 59696 |
9 | 262788 |
10 | 1148738 |
11 | 4989908 |
12 | 21551733 |
13 | 92596511 |
14 | 395921737 |
15 | 1685304092 |
16 | 7143861196 |
17 | 30163965903 |
18 | 126895681419 |
19 | 531986033218 |
20 | 2222961809367 |
21 | 9260148591001 |
22 | 38461580964389 |
23 | 159302487751844 |
24 | 658054630483936 |
25 | 2711429650817356 |
[1,1,6,30,143,660,3000,13448,59696,262788,1148738, 4989908,21551733,92596511,395921737,1685304092, 7143861196,30163965903,126895681419,531986033218, 2222961809367,9260148591001,38461580964389, 159302487751844,658054630483936,2711429650817356] |