n | a(n) |
---|---|
1 | 1 |
2 | 0 |
3 | 0 |
4 | 2 |
5 | 10 |
6 | 4 |
7 | 40 |
8 | 92 |
9 | 352 |
10 | 724 |
11 | 2680 |
12 | 14200 |
13 | 73712 |
14 | 365596 |
15 | 2279184 |
16 | 14772512 |
17 | 95815104 |
18 | 666090624 |
19 | 4968057848 |
20 | 39029188884 |
21 | 314666222712 |
22 | 2691008701644 |
23 | 24233937684440 |
24 | 226732487925864 |
[1,0,0,2,10,4,40,92,352,724,2680,14200,73712, 365596,2279184,14772512,95815104,666090624, 4968057848,39029188884,314666222712,2691008701644, 24233937684440,226732487925864] |