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| n | a(n) |
|---|---|
| 1 | 13 |
| 2 | 17 |
| 3 | 31 |
| 4 | 37 |
| 5 | 71 |
| 6 | 73 |
| 7 | 79 |
| 8 | 97 |
| 9 | 113 |
| 10 | 131 |
| 11 | 191 |
| 12 | 199 |
| 13 | 313 |
| 14 | 331 |
| 15 | 337 |
| 16 | 773 |
| 17 | 911 |
| 18 | 919 |
| 19 | 1171 |
| 20 | 7717 |
| 21 | 11113 |
| 22 | 11119 |
| 23 | 11177 |
| 24 | 11717 |
| 25 | 33331 |
| 26 | 77171 |
| 27 | 77711 |
| 28 | 79999 |
| 29 | 97777 |
| 30 | 99991 |
| 31 | 113111 |
| 32 | 131111 |
| 33 | 131113 |
| 34 | 131311 |
| 35 | 191999 |
| 36 | 199999 |
| 37 | 313133 |
| 38 | 313331 |
| 39 | 313333 |
| 40 | 331333 |
| 41 | 333737 |
| 42 | 377737 |
[13,17,31,37,71,73,79,97,113,131,191,199,313,331, 337,773,911,919,1171,7717,11113,11119,11177,11717, 33331,77171,77711,79999,97777,99991,113111,131111, 131113,131311,191999,199999,313133,313331,313333, 331333,333737,377737] |