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 | 7 |
| 2 | -84 |
| 3 | 1020 |
| 4 | -17220 |
| 5 | 313068 |
| 6 | -6075444 |
| 7 | 122709468 |
| 8 | -2553130020 |
| 9 | 54317619660 |
| 10 | -1175968479252 |
| 11 | 25819593611196 |
| 12 | -573476704909572 |
| 13 | 12861006710141100 |
| 14 | -290799326551852020 |
| 15 | 6621725329384239516 |
| 16 | -151707434284857934308 |
| 17 | 3494405505576163607436 |