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) |
|---|---|
| 4 | 12 |
| 5 | 180 |
| 6 | 4560 |
| 7 | 211680 |
| 8 | 17186624 |
| 9 | 2416430016 |
| 10 | 597615868800 |
| 11 | 266262716016000 |
| 12 | 218583901063537152 |
| 13 | 336744209796848156160 |
| 14 | 987653716558634390487040 |
| 15 | 5576385411303897176201779200 |
| 16 | 61117320790343064985205192540160 |