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 | 3 |
| 2 | 1 |
| 3 | -13 |
| 4 | -31 |
| 5 | 3 |
| 6 | 161 |
| 7 | 307 |
| 8 | -191 |
| 9 | -1917 |
| 10 | -2879 |
| 11 | 3827 |
| 12 | 22049 |
| 13 | 24963 |
| 14 | -60319 |
| 15 | -245453 |
| 16 | -189311 |
| 17 | 848643 |
| 18 | 2643841 |
| 19 | 1044467 |
| 20 | -11130271 |
| 21 | -27482877 |
| 22 | 685601 |
| 23 | 138785587 |
| 24 | 274143169 |
| 25 | -145641597 |
| 26 | -1661999039 |
| 27 | -2595790093 |
| 28 | 3118415009 |
| 29 | 19215780483 |