n | a(n) |
---|---|
2 | 1 |
3 | 0 |
4 | 0 |
5 | 6 |
6 | 0 |
7 | 30 |
8 | 24 |
9 | 168 |
10 | 288 |
11 | 1170 |
12 | 2760 |
13 | 9504 |
14 | 25776 |
15 | 84006 |
16 | 244104 |
17 | 779970 |
18 | 2356800 |
19 | 7487310 |
20 | 23167656 |
21 | 73639326 |
22 | 231348000 |
23 | 737718534 |
24 | 2341772136 |
25 | 7498417956 |
26 | 23982456384 |
27 | 77119604400 |
28 | 248088123192 |
29 | 800978437674 |
30 | 2588744704560 |
31 | 8388692108016 |
32 | 27217694697000 |
[1,0,0,6,0,30,24,168,288,1170,2760,9504,25776, 84006,244104,779970,2356800,7487310,23167656, 73639326,231348000,737718534,2341772136, 7498417956,23982456384,77119604400,248088123192, 800978437674,2588744704560,8388692108016, 27217694697000] |