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 | 24 |
| 5 | 600 |
| 6 | 10800 |
| 7 | 176400 |
| 8 | 2822400 |
| 9 | 45722880 |
| 10 | 762048000 |
| 11 | 13172544000 |
| 12 | 237105792000 |
| 13 | 4452319872000 |
| 14 | 87265469491200 |
| 15 | 1784975512320000 |
| 16 | 38079477596160000 |
| 17 | 846536078868480000 |
| 18 | 19591263539527680000 |
| 19 | 471496409184632832000 |
| 20 | 11787410229615820800000 |