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 | 124 |
| 2 | 421 |
| 3 | 1324 |
| 4 | 4231 |
| 5 | 13324 |
| 6 | 42331 |
| 7 | 1333324 |
| 8 | 4233331 |