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 | 0 |
| 2 | 72 |
| 3 | 1440 |
| 4 | 54216 |
| 5 | 2134080 |
| 6 | 93993120 |
| 7 | 4423628160 |
| 8 | 219463602120 |
| 9 | 11341793393280 |