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 | 0 |
| 2 | 3 |
| 3 | -17 |
| 4 | 169 |
| 5 | -2079 |
| 6 | 31261 |
| 7 | -554483 |
| 8 | 11336753 |
| 9 | -262517615 |
| 10 | 6791005621 |
| 11 | -194103134499 |
| 12 | 6074821125385 |
| 13 | -206616861429575 |
| 14 | 7588549099814957 |
| 15 | -299320105069298459 |
| 16 | 12619329503201165281 |
| 17 | -566312032570838608863 |
| 18 | 26952678355224681891685 |