n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 2 |
3 | 5 |
4 | 15 |
5 | 52 |
6 | 203 |
7 | 877 |
8 | 4140 |
9 | 21147 |
10 | 115975 |
11 | 678569 |
12 | 4213555 |
13 | 27643388 |
14 | 190878823 |
15 | 1382610179 |
16 | 10474709625 |
17 | 82784673008 |
18 | 680933897225 |
19 | 5816811952612 |
20 | 51505026270176 |
[1,1,2,5,15,52,203,877,4140,21147,115975,678569, 4213555,27643388,190878823,1382610179,10474709625, 82784673008,680933897225,5816811952612, 51505026270176] |