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| n | a(n) |
|---|---|
| 1 | 5 |
| 2 | 7 |
| 3 | 55 |
| 4 | 57 |
| 5 | 75 |
| 6 | 77 |
| 7 | 555 |
| 8 | 557 |
| 9 | 575 |
| 10 | 577 |
| 11 | 755 |
| 12 | 757 |
| 13 | 775 |
| 14 | 777 |
| 15 | 5555 |
| 16 | 5557 |
| 17 | 5575 |
| 18 | 5577 |
| 19 | 5755 |
| 20 | 5757 |
| 21 | 5775 |
| 22 | 5777 |
| 23 | 7555 |
| 24 | 7557 |
| 25 | 7575 |
| 26 | 7577 |
| 27 | 7755 |
| 28 | 7757 |
| 29 | 7775 |
| 30 | 7777 |
| 31 | 55555 |
| 32 | 55557 |
| 33 | 55575 |
| 34 | 55577 |
| 35 | 55755 |
| 36 | 55757 |
| 37 | 55775 |
| 38 | 55777 |
| 39 | 57555 |
| 40 | 57557 |
| 41 | 57575 |
| 42 | 57577 |
| 43 | 57755 |
| 44 | 57757 |
[5,7,55,57,75,77,555,557,575,577,755,757,775,777, 5555,5557,5575,5577,5755,5757,5775,5777,7555,7557, 7575,7577,7755,7757,7775,7777,55555,55557,55575, 55577,55755,55757,55775,55777,57555,57557,57575, 57577,57755,57757] |