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) |
|---|---|
| 3 | 1 |
| 4 | -656 |
| 5 | 484210 |
| 6 | -352504880 |
| 7 | 257015284435 |
| 8 | -187360965026144 |
| 9 | 136586400868021924 |
| 10 | -99571465386311288480 |
| 11 | 72587599955185580267365 |
| 12 | -52916360230556551635386480 |
| 13 | 38576026619154398792076180886 |