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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 5 |
| 5 | 7 |
| 6 | 8 |
| 7 | 15 |
| 8 | 23 |
| 9 | 31 |
| 10 | 87 |
| 11 | 111 |
| 12 | 119 |
| 13 | 167 |
| 14 | 335 |
| 15 | 1391 |
| 16 | 1455 |
| 17 | 1607 |
| 18 | 1679 |
| 19 | 1991 |
| 20 | 25887 |
| 21 | 26375 |
[1,2,4,5,7,8,15,23,31,87,111,119,167,335,1391, 1455,1607,1679,1991,25887,26375] |