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 | 15 |
| 2 | 55 |
| 3 | 5565 |
| 4 | 255255 |
| 5 | 12552555 |
| 6 | 585555531 |
| 7 | 5355555765 |
| 8 | 50525595555 |
| 9 | 5258558551555 |
| 10 | 555595555515 |
| 11 | 1551745755555555 |
| 12 | 39355555555552515 |
| 13 | 552550545955255555 |
| 14 | 13555559555595513555 |
| 15 | 455557505555605555585 |
| 16 | 5555558514557555255755 |
| 17 | 555457555855555784555355 |
| 18 | 505555585555455555505395 |