n | a(n) |
---|---|
1 | 0 |
2 | 0 |
3 | 648 |
4 | 3888 |
5 | 16200 |
6 | 58320 |
7 | 195048 |
8 | 625968 |
9 | 1960200 |
10 | 6045840 |
11 | 18468648 |
12 | 56068848 |
13 | 169533000 |
14 | 511252560 |
15 | 1539065448 |
16 | 4627812528 |
17 | 13904670600 |
18 | 41756478480 |
19 | 125354369448 |
20 | 376232977008 |
21 | 1129038669000 |
22 | 3387795483600 |
23 | 10164745404648 |
24 | 30496954122288 |
25 | 91496298184200 |
[0,0,648,3888,16200,58320,195048,625968,1960200, 6045840,18468648,56068848,169533000,511252560, 1539065448,4627812528,13904670600,41756478480, 125354369448,376232977008,1129038669000, 3387795483600,10164745404648,30496954122288, 91496298184200] |