n | a(n) |
---|---|
1 | 1 |
2 | 2 |
3 | 6 |
4 | 23 |
5 | 107 |
6 | 584 |
7 | 3660 |
8 | 25910 |
9 | 204564 |
10 | 1782520 |
11 | 16995202 |
12 | 176008542 |
13 | 1967664910 |
14 | 23618071616 |
15 | 302957562470 |
[1,2,6,23,107,584,3660,25910,204564,1782520, 16995202,176008542,1967664910,23618071616, 302957562470] |