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) |
|---|---|
| 2 | 2 |
| 3 | 2 |
| 4 | 2 |
| 5 | 6 |
| 6 | 120 |
| 7 | 120 |
| 8 | 2894220 |
| 9 | 397073040 |
| 10 | 1236161850 |
| 11 | 764907546690 |
| 12 | 8955490023480 |
| 13 | 138393712627170 |
| 14 | 8047290924923250 |