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| n | a(n) |
|---|---|
| 3 | 2 |
| 4 | 24 |
| 5 | 300 |
| 6 | 4320 |
| 7 | 72030 |
| 8 | 1376256 |
| 9 | 29760696 |
| 10 | 720000000 |
| 11 | 19292299290 |
| 12 | 567575838720 |
| 13 | 18197320924068 |
| 14 | 631732166467584 |
| 15 | 23613833496093750 |
| 16 | 945755921747804160 |
| 17 | 40410678374256222960 |
| 18 | 1835086247681868693504 |
| 19 | 88263072551692077310386 |
| 20 | 4482662400000000000000000 |
[2,24,300,4320,72030,1376256,29760696,720000000, 19292299290,567575838720,18197320924068, 631732166467584,23613833496093750, 945755921747804160,40410678374256222960, 1835086247681868693504,88263072551692077310386, 4482662400000000000000000] |