n | a(n) |
---|---|
0 | 1 |
1 | 0 |
2 | 2 |
3 | 6 |
4 | 36 |
5 | 240 |
6 | 1200 |
7 | 12600 |
8 | 58800 |
9 | 846720 |
10 | 3810240 |
11 | 69854400 |
12 | 307359360 |
13 | 6849722880 |
14 | 29682132480 |
15 | 779155977600 |
16 | 3339239904000 |
17 | 100919250432000 |
18 | 428906814336000 |
19 | 14668613050291200 |
20 | 61934143990118400 |
21 | 2364758225077248000 |
22 | 9931984545324441600 |
23 | 418798681661180620800 |
[1,0,2,6,36,240,1200,12600,58800,846720,3810240, 69854400,307359360,6849722880,29682132480, 779155977600,3339239904000,100919250432000, 428906814336000,14668613050291200, 61934143990118400,2364758225077248000, 9931984545324441600,418798681661180620800] |