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| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 3 |
| 3 | 5 |
| 4 | 7 |
| 5 | 17 |
| 6 | 29 |
| 7 | 71 |
| 8 | 181 |
| 9 | 281 |
| 10 | 293 |
| 11 | 607 |
| 12 | 829 |
| 13 | 929 |
| 14 | 2939 |
| 15 | 3929 |
| 16 | 8171 |
| 17 | 8293 |
| 18 | 9281 |
| 19 | 9293 |
| 20 | 18181 |
| 21 | 28181 |
| 22 | 39293 |
| 23 | 60607 |
| 24 | 70607 |
| 25 | 70717 |
| 26 | 71707 |
| 27 | 81707 |
| 28 | 81817 |
| 29 | 82939 |
| 30 | 170707 |
| 31 | 171707 |
| 32 | 181717 |
| 33 | 182929 |
| 34 | 281717 |
| 35 | 392929 |
| 36 | 393929 |
| 37 | 607181 |
| 38 | 707071 |
| 39 | 718171 |
[2,3,5,7,17,29,71,181,281,293,607,829,929,2939, 3929,8171,8293,9281,9293,18181,28181,39293,60607, 70607,70717,71707,81707,81817,82939,170707,171707, 181717,182929,281717,392929,393929,607181,707071, 718171] |