n | a(n) |
---|---|
1 | 1 |
2 | 0 |
3 | 0 |
4 | 2 |
5 | 10 |
6 | 4 |
7 | 28 |
8 | 20 |
9 | 56 |
10 | 72 |
11 | 288 |
12 | 1304 |
13 | 6368 |
14 | 22884 |
15 | 125864 |
16 | 755412 |
17 | 4565572 |
18 | 29862256 |
19 | 207238124 |
20 | 1540506028 |
21 | 11774180220 |
[1,0,0,2,10,4,28,20,56,72,288,1304,6368,22884, 125864,755412,4565572,29862256,207238124, 1540506028,11774180220] |