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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 5 |
| 5 | 4 |
| 6 | 14 |
| 7 | 36 |
| 8 | 30 |
| 9 | 576 |
| 10 | 55 |
| 11 | 14400 |
| 12 | 91 |
| 13 | 518400 |
| 14 | 140 |
| 15 | 25401600 |
| 16 | 204 |
| 17 | 1625702400 |
| 18 | 285 |
| 19 | 131681894400 |
| 20 | 385 |
| 21 | 13168189440000 |
| 22 | 506 |
| 23 | 1593350922240000 |
| 24 | 650 |
| 25 | 229442532802560000 |
| 26 | 819 |
| 27 | 38775788043632640000 |
| 28 | 1015 |
[0,1,1,1,5,4,14,36,30,576,55,14400,91,518400,140, 25401600,204,1625702400,285,131681894400,385, 13168189440000,506,1593350922240000,650, 229442532802560000,819,38775788043632640000,1015] |