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 | -1 |
| 4 | -8 |
| 5 | -204 |
| 6 | -24768 |
| 7 | -17867520 |
| 8 | -90077184000 |
| 9 | -3632037470208000 |
| 10 | -1317998813773824000000 |
| 11 | -4782755930355924782284800000 |
| 12 | -190912318579437962454242426880000000 |