n | a(n) |
---|---|
2 | 1 |
3 | 1 |
4 | 3 |
5 | 9 |
6 | 30 |
7 | 107 |
8 | 396 |
9 | 1506 |
10 | 5848 |
11 | 23087 |
12 | 92381 |
13 | 373830 |
14 | 1527192 |
15 | 6290054 |
16 | 26090780 |
17 | 108895558 |
18 | 456992576 |
19 | 1927176941 |
20 | 8162557837 |
21 | 34708427777 |
22 | 148110582311 |
23 | 634074235584 |
24 | 2722547715302 |
25 | 11721572763762 |
26 | 50591504811439 |
[1,1,3,9,30,107,396,1506,5848,23087,92381,373830, 1527192,6290054,26090780,108895558,456992576, 1927176941,8162557837,34708427777,148110582311, 634074235584,2722547715302,11721572763762, 50591504811439] |