n | a(n) |
---|---|
2 | 1 |
3 | 4 |
4 | 16 |
5 | 72 |
6 | 372 |
7 | 2208 |
8 | 14976 |
9 | 115200 |
10 | 996480 |
11 | 9607680 |
12 | 102366720 |
13 | 1195568640 |
14 | 15193785600 |
15 | 208728576000 |
16 | 3081867264000 |
17 | 48659595264000 |
18 | 817953583104000 |
19 | 14581909536768000 |
20 | 274755150544896000 |
21 | 5455208664170496000 |
22 | 113825841809670144000 |
[1,4,16,72,372,2208,14976,115200,996480,9607680, 102366720,1195568640,15193785600,208728576000, 3081867264000,48659595264000,817953583104000, 14581909536768000,274755150544896000, 5455208664170496000,113825841809670144000] |