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) |
|---|---|
| 19 | 1 |
| 20 | -19 |
| 21 | 171 |
| 22 | -969 |
| 23 | 3857 |
| 24 | -11286 |
| 25 | 24206 |
| 26 | -34542 |
| 27 | 14706 |
| 28 | 83011 |
| 29 | -294880 |
| 30 | 569753 |
| 31 | -680694 |
| 32 | 220286 |
| 33 | 1198672 |
| 34 | -3502612 |
| 35 | 5661867 |
| 36 | -5571579 |
| 37 | 791350 |
| 38 | 9721976 |
| 39 | -23494393 |
| 40 | 33415357 |
| 41 | -29225230 |
| 42 | 2352751 |
| 43 | 47086598 |
| 44 | -104517176 |
| 45 | 140834118 |
| 46 | -121255530 |