n | a(n) |
---|---|
0 | 0 |
1 | 0 |
2 | 0 |
3 | 0 |
4 | 4 |
5 | 18 |
6 | 102 |
7 | 786 |
8 | 3960 |
9 | 51450 |
10 | 675570 |
11 | 10804710 |
12 | 139674024 |
13 | 2793377664 |
14 | 58662908640 |
15 | 1798893694080 |
16 | 26985313555200 |
17 | 782574083010720 |
18 | 25992638958686400 |
19 | 857757034323189000 |
20 | 30021498596590300800 |
21 | 1563341714743040232000 |
22 | 64179292280096037844800 |
23 | 2631350957341279888915200 |
[0,0,0,0,4,18,102,786,3960,51450,675570,10804710, 139674024,2793377664,58662908640,1798893694080, 26985313555200,782574083010720,25992638958686400, 857757034323189000,30021498596590300800, 1563341714743040232000,64179292280096037844800, 2631350957341279888915200] |