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 | 109 |
| 4 | 909 |
| 5 | 10909 |
| 6 | 90909 |
| 7 | 1090909 |
| 8 | 9090909 |
| 9 | 13431958 |
| 10 | 25834963 |
| 11 | 32973507 |
| 12 | 38296415 |
| 13 | 45096237 |
| 14 | 51546969 |
| 15 | 94845303 |
| 16 | 96237045 |
| 17 | 109090909 |
| 18 | 113431958 |
| 19 | 126084879 |
| 20 | 132868745 |
| 21 | 132875488 |
| 22 | 133595248 |
| 23 | 134319558 |
| 24 | 134755956 |
| 25 | 134758658 |
| 26 | 137584878 |
| 27 | 143865844 |
| 28 | 153584878 |