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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 121 |
| 2 | 1211121 |
| 3 | 121112121211121 |
| 4 | 1211121212111211121112121211121 |
| 5 | 121112121211121112111212121112121211121212111211121112121211121 |
[1,121,1211121,121112121211121, 1211121212111211121112121211121, 12111212121112111211121212111212121112121211121112\ 1112121211121] |