n | a(n) |
---|---|
0 | 1 |
1 | 0 |
2 | 1 |
3 | 0 |
4 | 3 |
5 | 1 |
6 | 15 |
7 | 15 |
8 | 105 |
9 | 190 |
10 | 945 |
11 | 2410 |
12 | 10263 |
13 | 31890 |
14 | 127699 |
15 | 444458 |
16 | 1751685 |
17 | 6518736 |
18 | 25807445 |
19 | 100152288 |
20 | 401449271 |
21 | 1602902055 |
22 | 6519160851 |
23 | 26580508625 |
24 | 109656966853 |
25 | 454524861846 |
26 | 1899821492925 |
27 | 7982263725826 |
28 | 33757439931675 |
[1,0,1,0,3,1,15,15,105,190,945,2410,10263,31890, 127699,444458,1751685,6518736,25807445,100152288, 401449271,1602902055,6519160851,26580508625, 109656966853,454524861846,1899821492925, 7982263725826,33757439931675] |