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 | 9 |
| 3 | 189 |
| 4 | 2889 |
| 5 | 38889 |
| 6 | 488889 |
| 7 | 5888889 |
| 8 | 68888889 |
| 9 | 788888889 |
| 10 | 8888888889 |
| 11 | 98888888889 |
| 12 | 1088888888889 |
| 13 | 11888888888889 |
| 14 | 128888888888889 |
| 15 | 1388888888888889 |
| 16 | 14888888888888889 |
| 17 | 158888888888888889 |
| 18 | 1688888888888888889 |
| 19 | 17888888888888888889 |
| 20 | 188888888888888888889 |
| 21 | 1988888888888888888889 |