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| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 6 |
| 3 | 9 |
| 4 | 99 |
| 5 | 111 |
| 6 | 4444 |
| 7 | 111111111 |
| 8 | 555555555555 |
| 9 | 9999999999999999 |
| 10 | 111111111111111111 |
| 11 | 444444444444444444 |
| 12 | 555555555555555555555 |
| 13 | 777777777777777777777777 |
| 14 | 333333333333333333333333333333333 |
| 15 | 444444444444444444444444444444444444 |
[4,6,9,99,111,4444,111111111,555555555555, 9999999999999999,111111111111111111, 444444444444444444,555555555555555555555, 777777777777777777777777, 333333333333333333333333333333333, 444444444444444444444444444444444444] |