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 | 11 |
| 3 | 110 |
| 4 | 1109 |
| 5 | 11099 |
| 6 | 110999 |
| 7 | 1109999 |
| 8 | 11099999 |
| 9 | 110999999 |
| 10 | 1109999999 |
| 11 | 11099999999 |
| 12 | 110999999990 |
| 13 | 1109999999909 |
| 14 | 11099999999099 |
| 15 | 110999999990999 |
| 16 | 1109999999909990 |
| 17 | 11099999999099900 |
| 18 | 110999999990999009 |
| 19 | 1109999999909990099 |
| 20 | 11099999999099900999 |
| 21 | 110999999990999009990 |
| 22 | 1109999999909990099900 |
| 23 | 11099999999099900999000 |