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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 222 |
| 3 | 0 |
| 4 | 444444 |
| 5 | 55 |
| 6 | 666666 |
| 7 | 7777777777777777 |
| 8 | 888888888888888888 |
| 9 | 9999999999999999999999 |
| 10 | 1010101010101010101010101010 |
| 11 | 111111111111111111111111111111 |
| 12 | 121212 |
| 13 | 1313131313 |
[0,222,0,444444,55,666666,7777777777777777, 888888888888888888,9999999999999999999999, 1010101010101010101010101010, 111111111111111111111111111111,121212,1313131313] |