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 | 0 |
| 3 | 2 |
| 4 | 44 |
| 5 | 1008 |
| 6 | 34432 |
| 7 | 1629280 |
| 8 | 101401344 |
| 9 | 8030787968 |
| 10 | 788377273856 |
| 11 | 93933191303424 |
| 12 | 13350759115563520 |
| 13 | 2231133728986759168 |
| 14 | 433075048506207645696 |
| 15 | 96617322164029448916992 |
| 16 | 24549315871469898190266368 |
| 17 | 7047652261245574026565877760 |