n | a(n) |
---|---|
1 | 0 |
2 | 0 |
3 | 0 |
4 | 12 |
5 | 120 |
6 | 780 |
7 | 4212 |
8 | 20424 |
9 | 93360 |
10 | 409380 |
11 | 1749780 |
12 | 7338792 |
13 | 30394560 |
14 | 124705140 |
15 | 508291812 |
16 | 2061607224 |
17 | 8332140720 |
18 | 33585777060 |
19 | 135116412660 |
20 | 542785800072 |
21 | 2178110589600 |
22 | 8733345234900 |
[0,0,0,12,120,780,4212,20424,93360,409380,1749780, 7338792,30394560,124705140,508291812,2061607224, 8332140720,33585777060,135116412660,542785800072, 2178110589600,8733345234900] |