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) |
|---|---|
| 0 | 5 |
| 1 | 252 |
| 2 | 22522 |
| 3 | 2225222 |
| 4 | 222252222 |
| 5 | 22222522222 |
| 6 | 2222225222222 |
| 7 | 222222252222222 |
| 8 | 22222222522222222 |
| 9 | 2222222225222222222 |
| 10 | 222222222252222222222 |
| 11 | 22222222222522222222222 |
| 12 | 2222222222225222222222222 |
| 13 | 222222222222252222222222222 |
| 14 | 22222222222222522222222222222 |
| 15 | 2222222222222225222222222222222 |