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 | -2 |
| 3 | -7 |
| 4 | -11 |
| 5 | -43 |
| 6 | -65 |
| 7 | -259 |
| 8 | -146 |
| 9 | -1798 |
| 10 | 826 |
| 11 | -8116 |
| 12 | 17593 |
| 13 | -35089 |
| 14 | 301903 |
| 15 | -308464 |
| 16 | 3582403 |
| 17 | 157367 |
| 18 | 28816009 |
| 19 | 9388694 |
| 20 | 329375419 |
| 21 | -61352008 |
| 22 | 2991009094 |
| 23 | 509592773 |
| 24 | 23675224255 |
| 25 | 1207374806 |
| 26 | 229200996508 |
| 27 | -129896994130 |
| 28 | 2090952547882 |
| 29 | -816324790165 |
| 30 | 14079091274800 |