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 | -3 |
| 2 | 27 |
| 3 | -2223 |
| 4 | 1411020 |
| 5 | -6214529628 |
| 6 | 195816874969170 |
| 7 | -46124406363148894638 |
| 8 | 84075118460456018326675380 |
| 9 | -1215272486750697404426951511303060 |