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 | 1 |
| 3 | 2 |
| 4 | 7 |
| 5 | 308 |
| 6 | 1065372 |
| 7 | 5699432573835 |
| 8 | 742435596532024691458409520 |
| 9 | 1770094160863794205114840009375146894748207874734794924 |