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 | 255 |
| 3 | -6306 |
| 4 | 59230 |
| 5 | -331395 |
| 6 | 1348221 |
| 7 | -4416580 |
| 8 | 12360636 |
| 9 | -30686085 |
| 10 | 69313915 |
| 11 | -145044966 |
| 12 | 284936730 |
| 13 | -530793991 |
| 14 | 944995065 |
| 15 | -1617895560 |
| 16 | 2677071736 |
| 17 | -4298685705 |
| 18 | 6721274871 |
| 19 | -10262288170 |
| 20 | 15337711830 |
| 21 | -22485147531 |
| 22 | 32390726005 |
| 23 | -45920259276 |
| 24 | 64155054900 |
| 25 | -88432835725 |