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 | -2 |
| 2 | -2 |
| 3 | 28 |
| 4 | -74 |
| 5 | -92 |
| 6 | 1324 |
| 7 | -3656 |
| 8 | -4826 |
| 9 | 70228 |
| 10 | -197372 |
| 11 | -267896 |
| 12 | 3921724 |
| 13 | -11126936 |
| 14 | -15347432 |
| 15 | 225505648 |
| 16 | -643622906 |
| 17 | -897078476 |
| 18 | 13214495764 |
| 19 | -37869162392 |
| 20 | -53170602284 |
| 21 | 784672445368 |
| 22 | -2255295815192 |
| 23 | -3183829452272 |
| 24 | 47051201187676 |
| 25 | -135537088268792 |
| 26 | -192142210448216 |