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| n | a(n) |
|---|---|
| 0 | 21 |
| 1 | 23 |
| 2 | 25 |
| 3 | 27 |
| 4 | 29 |
| 5 | 30 |
| 6 | 33 |
| 7 | 36 |
| 8 | 41 |
| 9 | 45 |
| 10 | 53 |
| 11 | 113 |
| 12 | 201 |
| 13 | 1020 |
| 14 | 100001 |
| 15 | 111111111111111111111111111111111 |
[21,23,25,27,29,30,33,36,41,45,53,113,201,1020, 100001,111111111111111111111111111111111] |