n | a(n) |
---|---|
1 | 0 |
2 | 0 |
3 | 2 |
4 | 13 |
5 | 64 |
6 | 285 |
7 | 1210 |
8 | 5005 |
9 | 20384 |
10 | 82212 |
11 | 329460 |
12 | 1314610 |
13 | 5230016 |
14 | 20764055 |
15 | 82317690 |
16 | 326012925 |
17 | 1290244800 |
18 | 5103910680 |
19 | 20183646780 |
20 | 79802261190 |
21 | 315492902400 |
22 | 1247247742650 |
23 | 4930910180196 |
24 | 19495286167698 |
25 | 77085553829824 |
[0,0,2,13,64,285,1210,5005,20384,82212,329460, 1314610,5230016,20764055,82317690,326012925, 1290244800,5103910680,20183646780,79802261190, 315492902400,1247247742650,4930910180196, 19495286167698,77085553829824] |