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 | 1 |
| 2 | 2 |
| 3 | 3 |
| 4 | 15 |
| 5 | 176 |
| 6 | 526823 |
| 7 | 476715857290 |
| 8 | 26041797385576000582369625213281 |
| 9 | 6351070249807989850498698507055571178433293739297826225785529996796553557739865 |