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 | -9 |
| 3 | -61 |
| 4 | -9 |
| 5 | 9659 |
| 6 | 197631 |
| 7 | 1388099 |
| 8 | -51302169 |
| 9 | -2339721781 |
| 10 | -41290278129 |
| 11 | 536297904659 |
| 12 | 64956862241271 |
| 13 | 2152254297009179 |
| 14 | 6320179650231711 |
| 15 | -3288155212484644381 |
| 16 | -187761119883430045689 |