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 | 1 |
| 3 | -1 |
| 4 | -67 |
| 5 | -1 |
| 6 | -64397 |
| 7 | -113249 |
| 8 | -3679787 |
| 9 | -810304169 |
| 10 | -6040635661561 |
| 11 | -428305999661 |
| 12 | -16827172241810597 |
| 13 | -5620292762592913 |
| 14 | -1550760014054450957 |
| 15 | -4168373361283100017 |
| 16 | -8551022502876237590534947 |