n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 4 |
3 | 21 |
4 | 126 |
5 | 819 |
6 | 5611 |
7 | 39900 |
8 | 291719 |
9 | 2179181 |
10 | 16560175 |
11 | 127617168 |
12 | 994951887 |
13 | 7833555324 |
14 | 62196300997 |
15 | 497425570173 |
16 | 4003607595960 |
17 | 32404662671330 |
18 | 263586896132154 |
19 | 2153631763231319 |
20 | 17666722629907960 |
21 | 145449082369322208 |
22 | 1201414340736684702 |
[1,1,4,21,126,819,5611,39900,291719,2179181, 16560175,127617168,994951887,7833555324, 62196300997,497425570173,4003607595960, 32404662671330,263586896132154,2153631763231319, 17666722629907960,145449082369322208, 1201414340736684702] |