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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 7 |
| 4 | 111 |
| 5 | 343 |
| 6 | 757 |
| 7 | 10101 |
| 8 | 15751 |
| 9 | 30103 |
| 10 | 1001001 |
| 11 | 1255521 |
| 12 | 1403041 |
| 13 | 1837381 |
| 14 | 3372733 |
| 15 | 3521253 |
| 16 | 3847483 |
| 17 | 100010001 |
| 18 | 141979141 |
| 19 | 10000100001 |
| 20 | 14181118141 |
| 21 | 16112621161 |
| 22 | 35297579253 |
| 23 | 35475157453 |
| 24 | 37011411073 |
| 25 | 38735553783 |
| 26 | 1000001000001 |
| 27 | 1020505050201 |
[1,3,7,111,343,757,10101,15751,30103,1001001, 1255521,1403041,1837381,3372733,3521253,3847483, 100010001,141979141,10000100001,14181118141, 16112621161,35297579253,35475157453,37011411073, 38735553783,1000001000001,1020505050201] |