n | a(n) |
---|---|
4 | 1 |
5 | 4 |
6 | 20 |
7 | 100 |
8 | 525 |
9 | 2912 |
10 | 17052 |
11 | 105240 |
12 | 683100 |
13 | 4652340 |
14 | 33168850 |
15 | 246999480 |
16 | 1917186635 |
17 | 15480884720 |
18 | 129811538960 |
19 | 1128494172720 |
20 | 10155257740443 |
21 | 94465951576560 |
22 | 907162152191470 |
23 | 8982422995787780 |
24 | 91603484234843812 |
[1,4,20,100,525,2912,17052,105240,683100,4652340, 33168850,246999480,1917186635,15480884720, 129811538960,1128494172720,10155257740443, 94465951576560,907162152191470,8982422995787780, 91603484234843812] |