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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 3 |
| 3 | 40 |
| 4 | 495 |
| 5 | 6816 |
| 6 | 108255 |
| 7 | 1980672 |
| 8 | 41289759 |
| 9 | 968750080 |
| 10 | 25296994503 |
| 11 | 728148203520 |
| 12 | 22912992806847 |
| 13 | 782690956959744 |
| 14 | 28847447610890415 |
| 15 | 1141156999457800192 |
| 16 | 48228647947883167935 |
| 17 | 2168834125678237974528 |
[0,3,40,495,6816,108255,1980672,41289759, 968750080,25296994503,728148203520,22912992806847, 782690956959744,28847447610890415, 1141156999457800192,48228647947883167935, 2168834125678237974528] |