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 | 0 |
| 2 | 18 |
| 3 | 24 |
| 4 | -324 |
| 5 | -720 |
| 6 | 9234 |
| 7 | 33696 |
| 8 | -307926 |
| 9 | -1614000 |
| 10 | 10860480 |
| 11 | 78618672 |
| 12 | -385935492 |
| 13 | -3854459520 |
| 14 | 13226566500 |
| 15 | 189101997360 |
| 16 | -408244450788 |
| 17 | -9247223107008 |
| 18 | 9292147273170 |
| 19 | 449330421257568 |
| 20 | 41307157825920 |
| 21 | -21633699079357296 |
| 22 | -25580513164295232 |
| 23 | 1028997388914059808 |