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) |
|---|---|
| 1 | 1 |
| 2 | 672 |
| 3 | 4680 |
| 4 | 30240 |
| 5 | 435708 |
| 6 | 23569920 |
| 7 | 45532800 |
| 8 | 4138364160 |
| 9 | 14182439040 |
| 10 | 53798734080 |
| 11 | 153003540480 |
| 12 | 403031236608 |
| 13 | 518666803200 |