n | a(n) |
---|---|
0 | 0 |
1 | 0 |
2 | 0 |
3 | 3 |
4 | 6 |
5 | 20 |
6 | 270 |
7 | 1764 |
8 | 12600 |
9 | 169560 |
10 | 1937880 |
11 | 22300740 |
12 | 349806600 |
13 | 5556245760 |
14 | 89073856872 |
15 | 1678920566400 |
16 | 33550354656000 |
17 | 687175528253760 |
18 | 15462823882213440 |
19 | 370285712520237360 |
20 | 9180722384533375200 |
21 | 242398467521271149760 |
[0,0,0,3,6,20,270,1764,12600,169560,1937880, 22300740,349806600,5556245760,89073856872, 1678920566400,33550354656000,687175528253760, 15462823882213440,370285712520237360, 9180722384533375200,242398467521271149760] |