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) |
|---|---|
| 1 | 1 |
| 2 | -2 |
| 3 | 8 |
| 4 | -50 |
| 5 | 434 |
| 6 | -4864 |
| 7 | 66996 |
| 8 | -1095324 |
| 9 | 20724756 |
| 10 | -445310616 |
| 11 | 10708301328 |
| 12 | -284863999848 |
| 13 | 8304979127496 |
| 14 | -263299784899488 |
| 15 | 9018495674420592 |
| 16 | -331867682445078000 |
| 17 | 13057137391032043920 |
| 18 | -546957850901539335840 |