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 | 0 |
| 2 | 3 |
| 3 | -2 |
| 4 | 9 |
| 5 | -6 |
| 6 | 21 |
| 7 | -18 |
| 8 | 48 |
| 9 | -44 |
| 10 | 99 |
| 11 | -102 |
| 12 | 204 |
| 13 | -216 |
| 14 | 393 |
| 15 | -438 |
| 16 | 747 |
| 17 | -846 |
| 18 | 1362 |
| 19 | -1584 |
| 20 | 2448 |
| 21 | -2872 |
| 22 | 4275 |
| 23 | -5082 |
| 24 | 7356 |
| 25 | -8784 |
| 26 | 12390 |
| 27 | -14894 |
| 28 | 20592 |
| 29 | -24798 |
| 30 | 33651 |
| 31 | -40644 |
| 32 | 54336 |
| 33 | -65640 |
| 34 | 86535 |
| 35 | -104628 |
| 36 | 136356 |
| 37 | -164736 |
| 38 | 212388 |
| 39 | -256498 |
| 40 | 327690 |
| 41 | -395214 |