n | a(n) |
---|---|
0 | 0 |
1 | 1 |
2 | 6 |
3 | 36 |
4 | 240 |
5 | 1800 |
6 | 15120 |
7 | 141120 |
8 | 1451520 |
9 | 16329600 |
10 | 199584000 |
11 | 2634508800 |
12 | 37362124800 |
13 | 566658892800 |
14 | 9153720576000 |
15 | 156920924160000 |
16 | 2845499424768000 |
17 | 54420176498688000 |
18 | 1094805903679488000 |
19 | 23112569077678080000 |
20 | 510909421717094400000 |
21 | 11802007641664880640000 |
[0,1,6,36,240,1800,15120,141120,1451520,16329600, 199584000,2634508800,37362124800,566658892800, 9153720576000,156920924160000,2845499424768000, 54420176498688000,1094805903679488000, 23112569077678080000,510909421717094400000, 11802007641664880640000] |