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 | 12 |
| 3 | 124 |
| 4 | 1245 |
| 5 | 12457 |
| 6 | 1245710 |
| 7 | 124571011 |
| 8 | 12457101113 |
| 9 | 1245710111316 |
| 10 | 124571011131619 |
| 11 | 12457101113161920 |
| 12 | 1245710111316192023 |
| 13 | 124571011131619202325 |