n | a(n) |
---|---|
1 | 0 |
2 | 2 |
3 | 16 |
4 | 114 |
5 | 800 |
6 | 5602 |
7 | 39216 |
8 | 274514 |
9 | 1921600 |
10 | 13451202 |
11 | 94158416 |
12 | 659108914 |
13 | 4613762400 |
14 | 32296336802 |
15 | 226074357616 |
16 | 1582520503314 |
17 | 11077643523200 |
18 | 77543504662402 |
19 | 542804532636816 |
20 | 3799631728457714 |
21 | 26597422099204000 |
[0,2,16,114,800,5602,39216,274514,1921600, 13451202,94158416,659108914,4613762400, 32296336802,226074357616,1582520503314, 11077643523200,77543504662402,542804532636816, 3799631728457714,26597422099204000] |