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 | 2 |
| 2 | -16 |
| 3 | 212 |
| 4 | -3400 |
| 5 | 60384 |
| 6 | -1142960 |
| 7 | 22598832 |
| 8 | -461250208 |
| 9 | 9644611008 |
| 10 | -205537131008 |
| 11 | 4447969973888 |
| 12 | -97482797466624 |
| 13 | 2159242220999936 |
| 14 | -48260706692535552 |
| 15 | 1087076798266594048 |
| 16 | -24652590023639251456 |
| 17 | 562396337623786449920 |