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 | 12 |
| 2 | 12 |
| 3 | 123 |
| 4 | 12234 |
| 5 | 12345 |
| 6 | 123456 |
| 7 | 12234567 |
| 8 | 12345678 |
| 9 | 123456789 |
| 10 | 1023456789 |