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 | -65 |
| 3 | 635 |
| 4 | -1691507 |
| 5 | 2602903 |
| 6 | -30316306813 |
| 7 | 405644259179 |
| 8 | -281598937164737 |
| 9 | 491752927006687 |
| 10 | -38273845811539969069 |
| 11 | 68624716189056755839 |
| 12 | -372590717516807448774422779 |