n | a(n) |
---|---|
0 | 0 |
1 | 0 |
2 | 0 |
3 | 1 |
4 | 20 |
5 | 195 |
6 | 1430 |
7 | 9009 |
8 | 51688 |
9 | 278460 |
10 | 1434120 |
11 | 7141530 |
12 | 34648856 |
13 | 164663785 |
14 | 769491450 |
15 | 3546222225 |
16 | 16152872400 |
17 | 72846725160 |
18 | 325722299760 |
19 | 1445598337950 |
20 | 6373942543800 |
21 | 27942072562950 |
22 | 121863923024844 |
23 | 529043313674106 |
24 | 2287209524819120 |
[0,0,0,1,20,195,1430,9009,51688,278460,1434120, 7141530,34648856,164663785,769491450,3546222225, 16152872400,72846725160,325722299760, 1445598337950,6373942543800,27942072562950, 121863923024844,529043313674106,2287209524819120] |