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 | 678570 |
12 | 4213597 |
13 | 27644436 |
14 | 190899266 |
15 | 1382956734 |
16 | 10480097431 |
17 | 82863928963 |
18 | 682058946982 |
19 | 5832425824171 |
20 | 51718812364549 |
[1,1,2,5,15,52,203,877,4140,21147,115975,678570, 4213597,27644436,190899266,1382956734,10480097431, 82863928963,682058946982,5832425824171, 51718812364549] |