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 | 0 |
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 0 |
| 5 | 0 |
| 6 | 1 |
| 7 | 1 |
| 8 | -1 |
| 9 | -1 |
| 10 | 15 |
| 11 | 15 |
| 12 | -169 |
| 13 | -169 |
| 14 | 10753 |
| 15 | 10753 |
| 16 | -28713 |
| 17 | -28713 |
| 18 | 1586789 |
| 19 | 1586789 |
| 20 | -27542974 |
| 21 | -13771487 |
| 22 | 4694573547 |
| 23 | 4694573547 |
| 24 | -60230569205 |
| 25 | -60230569205 |
| 26 | 7328718272473 |
| 27 | 7328718272473 |
| 28 | -1043166080490099 |
| 29 | -1043166080490099 |
| 30 | 343459524172314625 |
| 31 | 343459524172314625 |