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 | 1 |
| 3 | 12 |
| 4 | 13 |
| 5 | 1234 |
| 6 | 15 |
| 7 | 123456 |
| 8 | 1357 |
| 9 | 124578 |
| 10 | 1379 |
| 11 | 12345678910 |
| 12 | 15711 |
| 13 | 123456789101112 |
| 14 | 13591113 |
| 15 | 12478111314 |
| 16 | 13579111315 |
| 17 | 12345678910111213141516 |
| 18 | 157111317 |
| 19 | 123456789101112131415161718 |