n | a(n) |
---|---|
0 | 0 |
1 | 0 |
2 | 1 |
3 | 6 |
4 | 36 |
5 | 240 |
6 | 1698 |
7 | 14304 |
8 | 118800 |
9 | 1118160 |
10 | 11705288 |
11 | 144092256 |
12 | 1738439808 |
13 | 24817158912 |
14 | 355309325280 |
15 | 5378578601760 |
16 | 86081749397280 |
17 | 1570394279039040 |
18 | 28281459220193088 |
19 | 572031558109589760 |
20 | 11458497230555094720 |
[0,0,1,6,36,240,1698,14304,118800,1118160, 11705288,144092256,1738439808,24817158912, 355309325280,5378578601760,86081749397280, 1570394279039040,28281459220193088, 572031558109589760,11458497230555094720] |