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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 21 |
| 3 | 2231 |
| 4 | 28261 |
| 5 | 611123 |
| 6 | 1200341 |
| 7 | 3427673 |
| 8 | 2202416417 |
| 9 | 11102657671 |
[1,21,2231,28261,611123,1200341,3427673, 2202416417,11102657671] |