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 | 33 |
| 3 | -731 |
| 4 | 25857 |
| 5 | -1311379 |
| 6 | 89060065 |
| 7 | -7778778091 |
| 8 | 849264442881 |
| 9 | -113234181108643 |
| 10 | 18073465545032353 |
| 11 | -3395124358886313595 |
| 12 | 740061366713642835201 |
| 13 | -185005977382236600650035 |