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 | 4 |
| 3 | 12 |
| 4 | 107 |
| 5 | 6439 |
| 6 | 7726965 |
| 7 | 2414519001532 |
| 8 | 56130437161079183223017 |
| 9 | 286386577668298409107773412840148848120595 |