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 | 0 |
| 3 | 1 |
| 4 | 1 |
| 5 | -1 |
| 6 | -7 |
| 7 | -13 |
| 8 | 169 |
| 9 | 233 |
| 10 | 17 |
| 11 | -18847 |
| 12 | -43957 |
| 13 | 26023 |
| 14 | 429007 |
| 15 | 31505483 |
| 16 | -31381783 |
| 17 | -753299101 |
| 18 | -7372705283 |
| 19 | 195152846389 |
| 20 | 632396244331 |
| 21 | -52258919107 |
| 22 | -447065769153911 |
| 23 | -13584264183406001 |
| 24 | 34831349327448893 |
| 25 | 674219621951483119 |
| 26 | 2113978805943481381 |
| 27 | -6602691591860999071 |
| 28 | -370308752490094361609 |
| 29 | -95867348590727618473 |
| 30 | 752151788353653780085507 |