n | a(n) |
---|---|
0 | 1 |
1 | 21 |
2 | 252 |
3 | 2233 |
4 | 16170 |
5 | 100926 |
6 | 560945 |
7 | 2837418 |
8 | 13266099 |
9 | 57994475 |
10 | 239170239 |
11 | 937026279 |
12 | 3507380170 |
13 | 12601619226 |
14 | 43628951025 |
15 | 146036139347 |
16 | 473924014599 |
17 | 1494785958435 |
18 | 4591920193357 |
19 | 13764656869425 |
20 | 40328218603134 |
[1,21,252,2233,16170,100926,560945,2837418, 13266099,57994475,239170239,937026279,3507380170, 12601619226,43628951025,146036139347,473924014599, 1494785958435,4591920193357,13764656869425, 40328218603134] |