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| n | a(n) |
|---|---|
| 1 | 13 |
| 2 | 31 |
| 3 | 11313331 |
| 4 | 11333131 |
| 5 | 13111333 |
| 6 | 13131133 |
| 7 | 13131331 |
| 8 | 13133311 |
| 9 | 13311313 |
| 10 | 31133131 |
| 11 | 33113131 |
| 12 | 1113131333 |
| 13 | 1131131333 |
| 14 | 1131311333 |
| 15 | 1131331133 |
| 16 | 1133111333 |
| 17 | 1133113133 |
| 18 | 1133133311 |
| 19 | 1133311313 |
| 20 | 1133313113 |
| 21 | 1133313131 |
| 22 | 1133331113 |
| 23 | 1311113333 |
| 24 | 1311311333 |
| 25 | 1311313313 |
[13,31,11313331,11333131,13111333,13131133, 13131331,13133311,13311313,31133131,33113131, 1113131333,1131131333,1131311333,1131331133, 1133111333,1133113133,1133133311,1133311313, 1133313113,1133313131,1133331113,1311113333, 1311311333,1311313313] |