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 | -1 |
| 2 | -1 |
| 3 | -5 |
| 4 | -7 |
| 5 | -1631 |
| 6 | -96547 |
| 7 | -40291823 |
| 8 | -16870575007 |
| 9 | -7075000252463 |
| 10 | -2969301738826267 |
| 11 | -13713149169712887583 |
| 12 | -10557203537780702505907 |