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 | 0 |
| 1 | 0 |
| 2 | 1 |
| 3 | 2 |
| 4 | 24 |
| 5 | 3136 |
| 6 | 53798080 |
| 7 | 15832480722303616 |
| 8 | 745527911414639917440582097294401 |
| 9 | 1653079675982713719400420113305863285438472194540328413077493166464 |