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 | 0 |
| 2 | 1 |
| 3 | 1 |
| 4 | 7 |
| 5 | 31 |
| 6 | 175 |
| 7 | 981 |
| 8 | 5719 |
| 9 | 33922 |
| 10 | 204687 |
| 11 | 1251460 |
| 12 | 7737807 |
| 13 | 48297536 |
| 14 | 303922983 |
| 15 | 1926038492 |
| 16 | 12281450455 |
| 17 | 78741558512 |
| 18 | 507301771543 |
| 19 | 3282586312161 |
| 20 | 21323849229781 |
| 21 | 139012437340660 |
| 22 | 909161626641121 |
| 23 | 5963576112550771 |
| 24 | 39223341189188339 |
| 25 | 258619428254117476 |
| 26 | 1709124801693650075 |