n | a(n) |
---|---|
2 | 1 |
3 | 3 |
4 | 12 |
5 | 60 |
6 | 345 |
7 | 2415 |
8 | 18480 |
9 | 166320 |
10 | 1596105 |
11 | 17557155 |
12 | 202951980 |
13 | 2638375740 |
14 | 35703612945 |
15 | 535554194175 |
16 | 8307234936000 |
17 | 141222993912000 |
18 | 2470641012464625 |
19 | 46942179236827875 |
20 | 914462992955011500 |
[1,3,12,60,345,2415,18480,166320,1596105,17557155, 202951980,2638375740,35703612945,535554194175, 8307234936000,141222993912000,2470641012464625, 46942179236827875,914462992955011500] |