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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 15 |
| 3 | 657 |
| 4 | 90111 |
| 5 | 39868737 |
| 6 | 57728430255 |
| 7 | 275769851453745 |
| 8 | 4367470887097715487 |
| 9 | 230051556728875753924449 |
| 10 | 40390820217552511124819066703 |
[1,15,657,90111,39868737,57728430255, 275769851453745,4367470887097715487, 230051556728875753924449, 40390820217552511124819066703] |