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) |
|---|---|
| 0 | 1 |
| 1 | 515 |
| 2 | 55155 |
| 3 | 5551555 |
| 4 | 555515555 |
| 5 | 55555155555 |
| 6 | 5555551555555 |
| 7 | 555555515555555 |
| 8 | 55555555155555555 |
| 9 | 5555555551555555555 |
| 10 | 555555555515555555555 |
| 11 | 55555555555155555555555 |
| 12 | 5555555555551555555555555 |
| 13 | 555555555555515555555555555 |
| 14 | 55555555555555155555555555555 |
| 15 | 5555555555555551555555555555555 |