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| n | a(n) |
|---|---|
| 2 | 1 |
| 3 | 1 |
| 4 | 12 |
| 5 | 6 |
| 6 | 180 |
| 7 | 10 |
| 8 | 560 |
| 9 | 1260 |
| 10 | 12600 |
| 11 | 1260 |
| 12 | 166320 |
| 13 | 13860 |
| 14 | 2522520 |
| 15 | 2702700 |
| 16 | 2882880 |
| 17 | 360360 |
| 18 | 110270160 |
| 19 | 2042040 |
| 20 | 775975200 |
| 21 | 162954792 |
| 22 | 56904848 |
| 23 | 2586584 |
| 24 | 1427794368 |
| 25 | 892371480 |
| 26 | 116008292400 |
| 27 | 120470149800 |
| 28 | 1124388064800 |
[1,1,12,6,180,10,560,1260,12600,1260,166320,13860, 2522520,2702700,2882880,360360,110270160,2042040, 775975200,162954792,56904848,2586584,1427794368, 892371480,116008292400,120470149800,1124388064800] |