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 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 0 |
| 6 | 0 |
| 7 | 0 |
| 8 | 0 |
| 9 | 0 |
| 10 | 0 |
| 11 | 3628800 |
| 12 | 43545600 |
| 13 | 283046400 |
| 14 | 1320883200 |
| 15 | 4953312000 |
| 16 | 15850598400 |
| 17 | 44910028800 |
| 18 | 115482931200 |
| 19 | 274271961600 |
| 20 | 609493248000 |
| 21 | 1279935820800 |
| 22 | 4644633666390681600 |
| 23 | 106826520356358566400 |
| 24 | 1281918194457262387200 |
| 25 | 10682651561168805120000 |