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) |
|---|---|
| 3 | 6 |
| 4 | 96 |
| 5 | 1200 |
| 6 | 14400 |
| 7 | 176400 |
| 8 | 2257920 |
| 9 | 30481920 |
| 10 | 435456000 |
| 11 | 6586272000 |
| 12 | 105380352000 |
| 13 | 1780927948800 |
| 14 | 31732897996800 |
| 15 | 594991837440000 |
| 16 | 11716762337280000 |
| 17 | 241867451105280000 |
| 18 | 5224336943874048000 |
| 19 | 117874102296158208000 |
| 20 | 2773508289321369600000 |