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) |
|---|---|
| 2 | -1 |
| 3 | -9 |
| 4 | -87 |
| 5 | -2925 |
| 6 | -75870 |
| 7 | -2811375 |
| 8 | -141027075 |
| 9 | -18407924325 |
| 10 | -1516052821500 |
| 11 | -153801543183750 |
| 12 | -18845978136851250 |
| 13 | -2744283682352086875 |
| 14 | -468435979952504313750 |
| 15 | -92643070481933918821875 |