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) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 36 |
| 5 | 1288 |
| 6 | 3732552 |
| 7 | 13845944773136 |
| 8 | 431339599553022278260254864 |
| 9 | 184905369551724915055273665254253822188651964997391392 |