n | a(n) |
---|---|
0 | 1 |
1 | 9 |
2 | 52 |
3 | 246 |
4 | 1039 |
5 | 4083 |
6 | 15274 |
7 | 55152 |
8 | 193957 |
9 | 668397 |
10 | 2266816 |
11 | 7589418 |
12 | 25143355 |
13 | 82571751 |
14 | 269173078 |
15 | 871958244 |
16 | 2809322833 |
17 | 9008574945 |
18 | 28768068460 |
19 | 91532284830 |
20 | 290283189991 |
21 | 917912770779 |
22 | 2894936303362 |
[1,9,52,246,1039,4083,15274,55152,193957,668397, 2266816,7589418,25143355,82571751,269173078, 871958244,2809322833,9008574945,28768068460, 91532284830,290283189991,917912770779, 2894936303362] |