n | a(n) |
---|---|
1 | 0 |
2 | 0 |
3 | 1 |
4 | 1 |
5 | 2 |
6 | 6 |
7 | 17 |
8 | 73 |
9 | 290 |
10 | 1274 |
11 | 5844 |
12 | 27750 |
13 | 135192 |
14 | 676263 |
15 | 3437509 |
16 | 17811771 |
17 | 93531354 |
18 | 497835030 |
19 | 2680058068 |
20 | 14577839412 |
21 | 80039070868 |
22 | 443164758244 |
23 | 2472713506356 |
[0,0,1,1,2,6,17,73,290,1274,5844,27750,135192, 676263,3437509,17811771,93531354,497835030, 2680058068,14577839412,80039070868,443164758244, 2472713506356] |