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 | -51 |
| 5 | 3485 |
| 6 | -219555 |
| 7 | 14107485 |
| 8 | -901984419 |
| 9 | 57741320029 |
| 10 | -3695215419555 |
| 11 | 236497451900765 |
| 12 | -15135778281070755 |
| 13 | 968690748238618461 |
| 14 | -61996192875273494691 |
| 15 | 3967756584209486471005 |
| 16 | -253936417546335462858915 |