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 | 0 |
| 3 | 0 |
| 4 | -2 |
| 5 | 0 |
| 6 | 28 |
| 7 | -64 |
| 8 | 39 |
| 9 | 224 |
| 10 | -884 |
| 11 | 1368 |
| 12 | 1350 |
| 13 | -12272 |
| 14 | 28752 |
| 15 | -11944 |
| 16 | -138873 |
| 17 | 494184 |
| 18 | -640856 |
| 19 | -1111568 |
| 20 | 7363194 |
| 21 | -15488224 |
| 22 | 1198848 |
| 23 | 93506112 |
| 24 | -293473869 |