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 | -3 |
| 2 | -7 |
| 3 | -527 |
| 4 | 164833 |
| 5 | -98248054847 |
| 6 | -3977703802948722503807 |
| 7 | -510456831154766758152181998159655209453904127 |