n | a(n) |
---|---|
0 | 1 |
1 | 4 |
2 | 20 |
3 | 112 |
4 | 672 |
5 | 4224 |
6 | 27456 |
7 | 183040 |
8 | 1244672 |
9 | 8599552 |
10 | 60196864 |
11 | 426008576 |
12 | 3042918400 |
13 | 21909012480 |
14 | 158840340480 |
15 | 1158600130560 |
16 | 8496400957440 |
17 | 62605059686400 |
18 | 463277441679360 |
19 | 3441489566760960 |
20 | 25654740406763520 |
21 | 191852841302753280 |
22 | 1438896309770649600 |
[1,4,20,112,672,4224,27456,183040,1244672,8599552, 60196864,426008576,3042918400,21909012480, 158840340480,1158600130560,8496400957440, 62605059686400,463277441679360,3441489566760960, 25654740406763520,191852841302753280, 1438896309770649600] |