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| n | a(n) |
|---|---|
| 1 | 3 |
| 2 | 6 |
| 3 | 54 |
| 4 | 864 |
| 5 | 12960 |
| 6 | 252720 |
| 7 | 5307120 |
| 8 | 130636800 |
| 9 | 3527193600 |
| 10 | 106697606400 |
| 11 | 3521021011200 |
| 12 | 127105948569600 |
| 13 | 4957131994214400 |
| 14 | 208390202679859200 |
| 15 | 9377559120593664000 |
| 16 | 450260112212951040000 |
[3,6,54,864,12960,252720,5307120,130636800, 3527193600,106697606400,3521021011200, 127105948569600,4957131994214400, 208390202679859200,9377559120593664000, 450260112212951040000] |