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 | -4 |
| 2 | 2 |
| 3 | 0 |
| 4 | 27 |
| 5 | -36 |
| 6 | 14 |
| 7 | -104 |
| 8 | 209 |
| 9 | -392 |
| 10 | 670 |
| 11 | -728 |
| 12 | 2278 |
| 13 | -4444 |
| 14 | 4808 |
| 15 | -9800 |
| 16 | 21750 |
| 17 | -35604 |
| 18 | 51906 |
| 19 | -91120 |
| 20 | 176285 |
| 21 | -290444 |
| 22 | 455168 |
| 23 | -741336 |
| 24 | 1372544 |
| 25 | -2419348 |
| 26 | 3490310 |
| 27 | -5765744 |
| 28 | 10788815 |
| 29 | -17086420 |
| 30 | 26221946 |
| 31 | -44374160 |