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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 7 |
| 4 | 9 |
| 5 | 13 |
| 6 | 15 |
| 7 | 31 |
| 8 | 33 |
| 9 | 37 |
| 10 | 51 |
| 11 | 73 |
| 12 | 99 |
| 13 | 111 |
| 14 | 115 |
| 15 | 151 |
| 16 | 339 |
| 17 | 393 |
| 18 | 511 |
| 19 | 777 |
| 20 | 933 |
| 21 | 9999 |
| 22 | 33333 |
| 23 | 55555 |
| 24 | 111111 |
| 25 | 777777 |
| 26 | 7777777 |
| 27 | 55555555 |
[1,3,7,9,13,15,31,33,37,51,73,99,111,115,151,339, 393,511,777,933,9999,33333,55555,111111,777777, 7777777,55555555] |