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| n | a(n) |
|---|---|
| 1 | 9999 |
| 2 | 99999 |
| 3 | 990099 |
| 4 | 999999 |
| 5 | 9901099 |
| 6 | 9905099 |
| 7 | 9993999 |
| 8 | 9996999 |
| 9 | 9997999 |
| 10 | 9998999 |
| 11 | 9999999 |
| 12 | 99999999 |
| 13 | 990959099 |
| 14 | 990969099 |
| 15 | 999010999 |
| 16 | 999020999 |
| 17 | 999030999 |
| 18 | 999040999 |
| 19 | 999070999 |
| 20 | 999929999 |
| 21 | 999939999 |
| 22 | 999969999 |
| 23 | 999989999 |
[9999,99999,990099,999999,9901099,9905099,9993999, 9996999,9997999,9998999,9999999,99999999, 990959099,990969099,999010999,999020999,999030999, 999040999,999070999,999929999,999939999,999969999, 999989999] |