n | a(n) |
---|---|
1 | 0 |
2 | 0 |
3 | 3 |
4 | 8 |
5 | 35 |
6 | 84 |
7 | 364 |
8 | 832 |
9 | 2997 |
10 | 8700 |
11 | 28281 |
12 | 55080 |
13 | 265720 |
14 | 794304 |
15 | 2006730 |
16 | 5240928 |
17 | 21511647 |
18 | 47028492 |
19 | 193587884 |
20 | 415388400 |
21 | 1607804226 |
[0,0,3,8,35,84,364,832,2997,8700,28281,55080, 265720,794304,2006730,5240928,21511647,47028492, 193587884,415388400,1607804226] |