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 | 0 |
| 1 | 1 |
| 2 | 1 |
| 3 | 3 |
| 4 | 8 |
| 5 | 23 |
| 6 | 62 |
| 7 | 178 |
| 8 | 495 |
| 9 | 1413 |
| 10 | 4015 |
| 11 | 11511 |
| 12 | 33000 |
| 13 | 95079 |
| 14 | 274163 |
| 15 | 792586 |
| 16 | 2294010 |
| 17 | 6649760 |
| 18 | 19295361 |
| 19 | 56048352 |
| 20 | 162940687 |
| 21 | 474069314 |
| 22 | 1380215558 |
| 23 | 4020916787 |
| 24 | 11720484787 |
| 25 | 34181438615 |
| 26 | 99733002848 |
| 27 | 291122869293 |
| 28 | 850134963598 |
| 29 | 2483484854325 |
| 30 | 7257482455313 |