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| n | a(n) |
|---|---|
| 1 | 9 |
| 2 | 81 |
| 3 | 387 |
| 4 | 2205 |
| 5 | 12015 |
| 6 | 66339 |
| 7 | 364869 |
| 8 | 2009223 |
| 9 | 11059965 |
| 10 | 60888177 |
| 11 | 335192787 |
| 12 | 1845279405 |
| 13 | 10158455727 |
| 14 | 55923440859 |
| 15 | 307864679445 |
| 16 | 1694829122631 |
| 17 | 9330221332989 |
| 18 | 51363898889337 |
| 19 | 282763934436339 |
| 20 | 1556646681947805 |
[9,81,387,2205,12015,66339,364869,2009223, 11059965,60888177,335192787,1845279405, 10158455727,55923440859,307864679445, 1694829122631,9330221332989,51363898889337, 282763934436339,1556646681947805] |