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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 3 |
| 4 | 0 |
| 5 | 30 |
| 6 | 360 |
| 7 | 6930 |
| 8 | 196728 |
| 9 | 8115660 |
| 10 | 433362960 |
| 11 | 28552545945 |
| 12 | 2276033387760 |
| 13 | 216132739612218 |
| 14 | 24118774853584320 |
| 15 | 3125242929676107240 |
| 16 | 465357404934002231280 |
| 17 | 78908446775174591638440 |
[0,0,0,3,0,30,360,6930,196728,8115660,433362960, 28552545945,2276033387760,216132739612218, 24118774853584320,3125242929676107240, 465357404934002231280,78908446775174591638440] |