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 | 2 |
| 3 | 42 |
| 4 | 984 |
| 5 | 48216 |
| 6 | 2869200 |
| 7 | 278125200 |
| 8 | 31015797120 |
| 9 | 4991834736000 |
| 10 | 896085889171200 |
| 11 | 215916261060729600 |
| 12 | 56895400548095155200 |