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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 24 |
| 5 | 48 |
| 6 | 5760 |
| 7 | 11520 |
| 8 | 35840 |
| 9 | 215040 |
| 10 | 51609600 |
| 11 | 103219200 |
| 12 | 13624934400 |
| 13 | 5449973760 |
| 14 | 1322526965760 |
| 15 | 3606891724800 |
| 16 | 158703235891200 |
| 17 | 105802157260800 |
| 18 | 14800210341396480 |
| 19 | 29600420682792960 |
| 20 | 3749386619820441600 |
[1,1,2,24,48,5760,11520,35840,215040,51609600, 103219200,13624934400,5449973760,1322526965760, 3606891724800,158703235891200,105802157260800, 14800210341396480,29600420682792960, 3749386619820441600] |