n | a(n) |
---|---|
1 | 0 |
2 | 40 |
3 | 264 |
4 | 1620 |
5 | 9156 |
6 | 49848 |
7 | 264300 |
8 | 1374048 |
9 | 7036116 |
10 | 35600376 |
11 | 178380156 |
12 | 886616784 |
13 | 4377006372 |
14 | 21483378600 |
15 | 104919416268 |
16 | 510169843584 |
17 | 2471194910580 |
18 | 11929478452824 |
19 | 57413851328028 |
20 | 275566856985648 |
[0,40,264,1620,9156,49848,264300,1374048,7036116, 35600376,178380156,886616784,4377006372, 21483378600,104919416268,510169843584, 2471194910580,11929478452824,57413851328028, 275566856985648] |