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) |
|---|---|
| 1 | 1 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 1 |
| 6 | 0 |
| 7 | 0 |
| 8 | 4 |
| 9 | -4 |
| 10 | 0 |
| 11 | 28 |
| 12 | -60 |
| 13 | 44 |
| 14 | 204 |
| 15 | -750 |
| 16 | 1084 |
| 17 | 979 |
| 18 | -8444 |
| 19 | 18886 |
| 20 | -7568 |
| 21 | -82269 |
| 22 | 280288 |
| 23 | -348172 |
| 24 | -576712 |
| 25 | 3677331 |
| 26 | -7445964 |
| 27 | 569558 |
| 28 | 41740944 |
| 29 | -126624684 |