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 | 4 |
| 2 | 48 |
| 3 | 720 |
| 4 | 50400 |
| 5 | 665280 |
| 6 | 43243200 |
| 7 | 2205403200 |
| 8 | 293318625600 |
| 9 | 26985313555200 |
| 10 | 782574093100800 |
| 11 | 72779390658374400 |
| 12 | 8976124847866176000 |
| 13 | 368021118762513216000 |
| 14 | 52222196752400625350400 |
| 15 | 2454443247362829391468800 |
| 16 | 1691111397432989450722003200 |