n | a(n) |
---|---|
0 | 0 |
1 | 0 |
2 | 1 |
3 | 4 |
4 | 30 |
5 | 216 |
6 | 1440 |
7 | 11040 |
8 | 112560 |
9 | 1229760 |
10 | 14333760 |
11 | 179988480 |
12 | 2259290880 |
13 | 30656102400 |
14 | 446269824000 |
15 | 6949355212800 |
16 | 123855443712000 |
17 | 2320686111744000 |
18 | 45616912653312000 |
19 | 939726185029632000 |
20 | 20166054423330816000 |
[0,0,1,4,30,216,1440,11040,112560,1229760, 14333760,179988480,2259290880,30656102400, 446269824000,6949355212800,123855443712000, 2320686111744000,45616912653312000, 939726185029632000,20166054423330816000] |