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| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 503 |
| 3 | 48018 |
| 4 | 4107189 |
| 5 | 354544219 |
| 6 | 30591390580 |
| 7 | 2639211238177 |
| 8 | 227683834800188 |
[4,503,48018,4107189,354544219,30591390580, 2639211238177,227683834800188] |