n | a(n) |
---|---|
1 | 1 |
2 | 4 |
3 | 20 |
4 | 100 |
5 | 720 |
6 | 7920 |
7 | 156960 |
8 | 4978909 |
9 | 162844632 |
10 | 9658482053 |
11 | 917891979225 |
12 | 113051563311936 |
13 | 21440096665285608 |
14 | 6394092372716939840 |
15 | 2723634378368868283440 |
16 | 1747667851609071536512000 |
[1,4,20,100,720,7920,156960,4978909,162844632, 9658482053,917891979225,113051563311936, 21440096665285608,6394092372716939840, 2723634378368868283440,1747667851609071536512000] |