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 | 1 |
| 3 | 0 |
| 4 | -3 |
| 5 | -9 |
| 6 | -15 |
| 7 | -7 |
| 8 | 50 |
| 9 | 203 |
| 10 | 429 |
| 11 | 382 |
| 12 | -1045 |
| 13 | -5845 |
| 14 | -14751 |
| 15 | -18627 |
| 16 | 20255 |
| 17 | 184818 |
| 18 | 549630 |
| 19 | 879632 |
| 20 | -156085 |
| 21 | -6025489 |
| 22 | -21267251 |
| 23 | -40911195 |
| 24 | -17629620 |
| 25 | 193929269 |
| 26 | 835617523 |
| 27 | 1881543582 |
| 28 | 1674869775 |
| 29 | -5855762293 |
| 30 | -32848801375 |
| 31 | -85601962056 |
| 32 | -108647926359 |