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 | 2 |
| 3 | 12 |
| 4 | 121 |
| 5 | 212 |
| 6 | 1212 |
| 7 | 12121 |
| 8 | 21212 |
| 9 | 121212 |
| 10 | 1212121 |
| 11 | 2121212 |
| 12 | 12121212 |
| 13 | 121212121 |
| 14 | 212121212 |
| 15 | 1212121212 |
| 16 | 12121212121 |
| 17 | 21212121212 |
| 18 | 121212121212 |
| 19 | 1212121212121 |
| 20 | 2121212121212 |
| 21 | 12121212121212 |
| 22 | 121212121212121 |
| 23 | 212121212121212 |
| 24 | 1212121212121212 |
| 25 | 12121212121212121 |