n | a(n) |
---|---|
0 | 0 |
1 | 0 |
2 | 4 |
3 | 30 |
4 | 240 |
5 | 2140 |
6 | 21300 |
7 | 235074 |
8 | 2853760 |
9 | 37819800 |
10 | 543445380 |
11 | 8416452550 |
12 | 139753069104 |
13 | 2476581106740 |
14 | 46648575724660 |
15 | 930581784937770 |
16 | 19597766647728000 |
17 | 434455097953799344 |
18 | 10112163333554834820 |
19 | 246539064280189932270 |
20 | 6282671083849941925360 |
[0,0,4,30,240,2140,21300,235074,2853760,37819800, 543445380,8416452550,139753069104,2476581106740, 46648575724660,930581784937770,19597766647728000, 434455097953799344,10112163333554834820, 246539064280189932270,6282671083849941925360] |