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 | 1 |
| 2 | 9 |
| 3 | 55 |
| 4 | 99 |
| 5 | 999 |
| 6 | 7777 |
| 7 | 9999 |
| 8 | 22222 |
| 9 | 99999 |
| 10 | 999999 |
| 11 | 4444444 |
| 12 | 9999999 |
| 13 | 88888888 |
| 14 | 99999999 |
| 15 | 909090909 |
| 16 | 999999999 |
| 17 | 1111111111 |
| 18 | 9999999999 |
| 19 | 55555555555 |
| 20 | 99999999999 |
| 21 | 999999999999 |
| 22 | 7777777777777 |
| 23 | 9999999999999 |
| 24 | 22222222222222 |
| 25 | 99999999999999 |
| 26 | 999999999999999 |
| 27 | 4444444444444444 |
| 28 | 9999999999999999 |
| 29 | 88888888888888888 |