n | a(n) |
---|---|
0 | 0 |
1 | 1 |
2 | 20 |
3 | 380 |
4 | 7200 |
5 | 136400 |
6 | 2584000 |
7 | 48952000 |
8 | 927360000 |
9 | 17568160000 |
10 | 332816000000 |
11 | 6304956800000 |
12 | 119442816000000 |
13 | 2262757184000000 |
14 | 42866287360000000 |
15 | 812070603520000000 |
16 | 15384086323200000000 |
[0,1,20,380,7200,136400,2584000,48952000, 927360000,17568160000,332816000000,6304956800000, 119442816000000,2262757184000000, 42866287360000000,812070603520000000, 15384086323200000000] |