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 | 10 |
| 3 | 57915 |
| 4 | 8235313944000 |
| 5 | 1077099640691257742845893750 |
| 6 | 4629575796245443900868634734946423885068807034000 |