n | a(n) |
---|---|
1 | 0 |
2 | 0 |
3 | 0 |
4 | 6 |
5 | 90 |
6 | 1080 |
7 | 12600 |
8 | 151200 |
9 | 1905120 |
10 | 25401600 |
11 | 359251200 |
12 | 5388768000 |
13 | 85621536000 |
14 | 1438441804800 |
15 | 25499650176000 |
16 | 475993469952000 |
17 | 9336794987520000 |
18 | 192071211171840000 |
19 | 4135933413900288000 |
20 | 93058501812756480000 |
21 | 2184137777840578560000 |
22 | 53390034569436364800000 |
[0,0,0,6,90,1080,12600,151200,1905120,25401600, 359251200,5388768000,85621536000,1438441804800, 25499650176000,475993469952000,9336794987520000, 192071211171840000,4135933413900288000, 93058501812756480000,2184137777840578560000, 53390034569436364800000] |