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| n | a(n) |
|---|---|
| 0 | -1 |
| 1 | -1 |
| 2 | 5 |
| 3 | 71 |
| 4 | 1223 |
| 5 | 34619 |
| 6 | 1350629 |
| 7 | 65717315 |
| 8 | 3812715311 |
| 9 | 256504939703 |
| 10 | 19615931258309 |
| 11 | 1679703910478879 |
| 12 | 159161100818585975 |
| 13 | 16530378160682622131 |
| 14 | 1867052905777649782373 |
| 15 | 227820142193907368696219 |
| 16 | 29863924388750996422840799 |
| 17 | 4185177460305652712999777135 |
[-1,-1,5,71,1223,34619,1350629,65717315, 3812715311,256504939703,19615931258309, 1679703910478879,159161100818585975, 16530378160682622131,1867052905777649782373, 227820142193907368696219, 29863924388750996422840799, 4185177460305652712999777135] |