n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 3 |
3 | 9 |
4 | 31 |
5 | 108 |
6 | 391 |
7 | 1431 |
8 | 5319 |
9 | 19926 |
10 | 75252 |
11 | 285750 |
12 | 1090491 |
13 | 4177774 |
14 | 16060401 |
15 | 61916977 |
16 | 239307063 |
17 | 926929746 |
18 | 3597296770 |
19 | 13984508500 |
20 | 54448030092 |
21 | 212282062488 |
22 | 828673761978 |
23 | 3238495227846 |
24 | 12669206034339 |
[1,1,3,9,31,108,391,1431,5319,19926,75252,285750, 1090491,4177774,16060401,61916977,239307063, 926929746,3597296770,13984508500,54448030092, 212282062488,828673761978,3238495227846, 12669206034339] |