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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 12 |
| 3 | 123 |
| 4 | 1231 |
| 5 | 12312 |
| 6 | 123123 |
| 7 | 1231231 |
| 8 | 12312312 |
| 9 | 123123123 |
| 10 | 1231231231 |
| 11 | 12312312312 |
| 12 | 123123123123 |
| 13 | 1231231231231 |
| 14 | 12312312312312 |
| 15 | 123123123123123 |
| 16 | 1231231231231231 |
| 17 | 12312312312312312 |
| 18 | 123123123123123123 |
| 19 | 1231231231231231231 |
| 20 | 12312312312312312312 |
[1,12,123,1231,12312,123123,1231231,12312312, 123123123,1231231231,12312312312,123123123123, 1231231231231,12312312312312,123123123123123, 1231231231231231,12312312312312312, 123123123123123123,1231231231231231231, 12312312312312312312] |