n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 1 |
3 | 2 |
4 | 6 |
5 | 18 |
6 | 58 |
7 | 186 |
8 | 570 |
9 | 1680 |
10 | 4878 |
11 | 14058 |
12 | 40200 |
13 | 114450 |
14 | 325290 |
15 | 923846 |
16 | 2624730 |
17 | 7465410 |
18 | 21261828 |
19 | 60647370 |
20 | 173288724 |
21 | 496014934 |
22 | 1422223506 |
23 | 4084793082 |
24 | 11751102060 |
25 | 33857989968 |
26 | 97697014590 |
27 | 282295318536 |
28 | 816759712080 |
29 | 2366027865810 |
30 | 6861964439314 |
[1,1,1,2,6,18,58,186,570,1680,4878,14058,40200, 114450,325290,923846,2624730,7465410,21261828, 60647370,173288724,496014934,1422223506, 4084793082,11751102060,33857989968,97697014590, 282295318536,816759712080,2366027865810, 6861964439314] |