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 | 2 |
| 4 | 4 |
| 5 | 24 |
| 6 | 17280 |
| 7 | 6270566400 |
| 8 | 40146509439381484339200000 |
| 9 | 10648976440273061914760324802543763313620156416000000000000 |