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 | -6 |
| 2 | 27 |
| 3 | -90 |
| 4 | 189 |
| 5 | 0 |
| 6 | -1782 |
| 7 | 6318 |
| 8 | 0 |
| 9 | -90882 |
| 10 | 360126 |
| 11 | 0 |
| 12 | -5985819 |
| 13 | 24931800 |
| 14 | 0 |
| 15 | -446371074 |
| 16 | 1912892355 |
| 17 | 0 |
| 18 | -35840971530 |
| 19 | 156454458930 |
| 20 | 0 |
| 21 | -3022929941616 |
| 22 | 13367712796110 |
| 23 | 0 |
| 24 | -264079216747476 |
| 25 | 1179032268616902 |
| 26 | 0 |
| 27 | -23685874363658232 |
| 28 | 106533987128598645 |
| 29 | 0 |