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| n | a(n) |
|---|---|
| 1 | 3 |
| 2 | 15 |
| 3 | 120 |
| 4 | 1320 |
| 5 | 21120 |
| 6 | 401280 |
| 7 | 9630720 |
| 8 | 260029440 |
| 9 | 8320942080 |
| 10 | 324516741120 |
| 11 | 13629703127040 |
| 12 | 667855453224960 |
| 13 | 36064194474147840 |
| 14 | 2055659085026426880 |
| 15 | 127450863271638466560 |
| 16 | 8794109565743054192640 |
| 17 | 668352326996472118640640 |
[3,15,120,1320,21120,401280,9630720,260029440, 8320942080,324516741120,13629703127040, 667855453224960,36064194474147840, 2055659085026426880,127450863271638466560, 8794109565743054192640,668352326996472118640640] |