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 | 6 |
| 4 | 32 |
| 5 | 620 |
| 6 | 259960 |
| 7 | 62059718088 |
| 8 | 3840971361624607057216 |
| 9 | 14752998887519276350335088653216965113845136 |