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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 6 |
| 3 | 4 |
| 4 | 216 |
| 5 | 198 |
| 6 | 36 |
| 7 | 23040 |
| 8 | 24640 |
| 9 | 7200 |
| 10 | 576 |
| 11 | 5400000 |
| 12 | 6375000 |
| 13 | 2362500 |
| 14 | 328800 |
| 15 | 14400 |
| 16 | 2351462400 |
| 17 | 2982873600 |
| 18 | 1285956000 |
| 19 | 238533120 |
| 20 | 19051200 |
| 21 | 518400 |
| 22 | 1707698764800 |
| 23 | 2291162509440 |
| 24 | 1100516981760 |
| 25 | 245735819280 |
| 26 | 27025656000 |
| 27 | 1383117120 |
| 28 | 25401600 |
[1,6,4,216,198,36,23040,24640,7200,576,5400000, 6375000,2362500,328800,14400,2351462400, 2982873600,1285956000,238533120,19051200,518400, 1707698764800,2291162509440,1100516981760, 245735819280,27025656000,1383117120,25401600] |