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 | 24 |
| 1 | 1920 |
| 2 | 193536 |
| 3 | 66355200 |
| 4 | 13624934400 |
| 5 | 243465191424000 |
| 6 | 4944216195072000 |
| 7 | 9990141980442624000 |
| 8 | 39391717484295880704000 |
| 9 | 465236915972420822630400000 |