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| n | a(n) |
|---|---|
| 1 | 7 |
| 2 | 55 |
| 3 | 595 |
| 4 | 727 |
| 5 | 787 |
| 6 | 5995 |
| 7 | 59995 |
| 8 | 72127 |
| 9 | 72727 |
| 10 | 78187 |
| 11 | 78787 |
| 12 | 599995 |
| 13 | 5999995 |
| 14 | 7212127 |
| 15 | 7218127 |
| 16 | 7272727 |
| 17 | 7278727 |
| 18 | 7812187 |
| 19 | 7818187 |
| 20 | 7872787 |
| 21 | 7878787 |
| 22 | 59999995 |
| 23 | 599999995 |
| 24 | 721212127 |
| 25 | 721272127 |
| 26 | 721818127 |
| 27 | 721878127 |
| 28 | 727212727 |
[7,55,595,727,787,5995,59995,72127,72727,78187, 78787,599995,5999995,7212127,7218127,7272727, 7278727,7812187,7818187,7872787,7878787,59999995, 599999995,721212127,721272127,721818127,721878127, 727212727] |