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| n | a(n) |
|---|---|
| 1 | 9 |
| 2 | 99 |
| 3 | 999 |
| 4 | 9999 |
| 5 | 99999 |
| 6 | 999999 |
| 7 | 9999999 |
| 8 | 99999999 |
| 9 | 999999999 |
| 10 | 9999999999 |
| 11 | 36363636362 |
| 12 | 45454545453 |
| 13 | 54545454544 |
| 14 | 63636363635 |
| 15 | 72727272726 |
| 16 | 81818181817 |
| 17 | 90909090908 |
| 18 | 99999999999 |
| 19 | 999999999999 |
| 20 | 9999999999999 |
[9,99,999,9999,99999,999999,9999999,99999999, 999999999,9999999999,36363636362,45454545453, 54545454544,63636363635,72727272726,81818181817, 90909090908,99999999999,999999999999, 9999999999999] |