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 | 25 |
| 2 | 233 |
| 3 | -13775 |
| 4 | -618383 |
| 5 | 6139625 |
| 6 | 1365521305 |
| 7 | 19697634625 |
| 8 | -3254549595295 |
| 9 | -143135522066375 |
| 10 | 7903662920541385 |
| 11 | 758682819513724625 |
| 12 | -15113524025531336495 |
| 13 | -3946682083630844048375 |
| 14 | -21648533656663410430855 |
| 15 | 21118177933549486876710625 |