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 | 1 |
| 1 | 2 |
| 2 | 9 |
| 3 | 38 |
| 4 | 161 |
| 5 | 682 |
| 6 | 2889 |
| 7 | 12238 |
| 8 | 51841 |
| 9 | 219602 |
| 10 | 930249 |
| 11 | 3940598 |
| 12 | 16692641 |
| 13 | 70711162 |
| 14 | 299537289 |
| 15 | 1268860318 |
| 16 | 5374978561 |
| 17 | 22768774562 |
| 18 | 96450076809 |
| 19 | 408569081798 |
| 20 | 1730726404001 |
| 21 | 7331474697802 |
| 22 | 31056625195209 |