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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 9 |
| 2 | 721 |
| 3 | 82089 |
| 4 | 12230001 |
| 5 | 2120202009 |
| 6 | 406989480241 |
| 7 | 84181340789289 |
| 8 | 18415254766978801 |
| 9 | 4208936841232398009 |
| 10 | 996304344364456946721 |
| 11 | 242690365333454553543609 |
| 12 | 60541628771062122533055441 |
| 13 | 15409152448094957808105486009 |
[1,9,721,82089,12230001,2120202009,406989480241, 84181340789289,18415254766978801, 4208936841232398009,996304344364456946721, 242690365333454553543609, 60541628771062122533055441, 15409152448094957808105486009] |