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 | 0 |
| 2 | 89 |
| 3 | 0 |
| 4 | 8999 |
| 5 | 89899 |
| 6 | 888989 |
| 7 | 8888989 |
| 8 | 88888999 |
| 9 | 888898889 |
| 10 | 8888888989 |
| 11 | 88888888999 |
| 12 | 888888898999 |
| 13 | 8888888999899 |
| 14 | 88888888888889 |
| 15 | 888888888898999 |
| 16 | 8888888888989999 |
| 17 | 88888888888888889 |
| 18 | 888888888888898889 |