n | a(n) |
---|---|
0 | 0 |
1 | 0 |
2 | 0 |
3 | 6 |
4 | 12 |
5 | 40 |
6 | 540 |
7 | 3528 |
8 | 25200 |
9 | 324000 |
10 | 3648960 |
11 | 41690880 |
12 | 622274400 |
13 | 9573033600 |
14 | 150465579264 |
15 | 2705877820800 |
16 | 51819600268800 |
17 | 1028013655818240 |
18 | 22086154437442560 |
19 | 504188626820659200 |
20 | 11997041025160396800 |
21 | 301999960230701322240 |
[0,0,0,6,12,40,540,3528,25200,324000,3648960, 41690880,622274400,9573033600,150465579264, 2705877820800,51819600268800,1028013655818240, 22086154437442560,504188626820659200, 11997041025160396800,301999960230701322240] |