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) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 0 |
| 3 | 4 |
| 4 | 0 |
| 5 | 0 |
| 6 | 80 |
| 7 | 48 |
| 8 | 0 |
| 9 | 3328 |
| 10 | 1920 |
| 11 | 0 |
| 12 | 270080 |
| 13 | 131328 |
| 14 | 0 |
| 15 | 3257736 |
| 16 | 16379904 |
| 17 | 0 |
| 18 | 5750476800 |
| 19 | 2942582784 |
| 20 | 0 |
| 21 | 1376249266176 |
| 22 | 706948005888 |
| 23 | 0 |
| 24 | 430415593603072 |