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 | -31 |
| 2 | 3809 |
| 3 | -620190 |
| 4 | 111669570 |
| 5 | -21246138749 |
| 6 | 4186228503780 |
| 7 | -845058129488699 |
| 8 | 173647689528542310 |
| 9 | -36170751826552656600 |
| 10 | 7615730581866678419370 |
| 11 | -1617501058117655447210580 |
| 12 | 346019784662582818549094159 |