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 | 24 |
| 5 | 120 |
| 6 | 720 |
| 7 | 5040 |
| 8 | 80640 |
| 9 | 2177280 |
| 10 | 87091200 |
| 11 | 4790016000 |
| 12 | 344881152000 |
| 13 | 31384184832000 |
| 14 | 7030057402368000 |
| 15 | 2847173247959040000 |
| 16 | 1822190878693785600000 |
| 17 | 1703748471578689536000000 |