This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
| n | a(n) |
|---|---|
| 1 | 5 |
| 2 | 7 |
| 3 | 557 |
| 4 | 577 |
| 5 | 757 |
| 6 | 5557 |
| 7 | 7577 |
| 8 | 7757 |
| 9 | 57557 |
| 10 | 75557 |
| 11 | 75577 |
| 12 | 77557 |
| 13 | 555557 |
| 14 | 575557 |
| 15 | 575777 |
| 16 | 577757 |
| 17 | 757577 |
| 18 | 775757 |
| 19 | 775777 |
| 20 | 5555777 |
| 21 | 5557757 |
| 22 | 5575777 |
| 23 | 5577577 |
| 24 | 5755577 |
| 25 | 5775557 |
| 26 | 5777557 |
| 27 | 7575577 |
| 28 | 7577777 |
| 29 | 55555777 |
| 30 | 55575757 |
| 31 | 55755757 |
| 32 | 55757777 |
| 33 | 57557557 |