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 | 199 |
| 2 | 91199 |
| 3 | 111119 |
| 4 | 111919 |
| 5 | 119191 |
| 6 | 991999 |
| 7 | 1191119 |
| 8 | 1191191 |
| 9 | 1191991 |
| 10 | 11111911 |
| 11 | 11191991 |
| 12 | 11919991 |
| 13 | 19111991 |
| 14 | 91111199 |
| 15 | 111111199 |
| 16 | 111199199 |
| 17 | 191111119 |
| 18 | 199991999 |
| 19 | 919919999 |
| 20 | 1111111999 |
| 21 | 1191111991 |
| 22 | 1199111191 |
| 23 | 1911199999 |