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 | -14 |
| 3 | 162 |
| 4 | -2270 |
| 5 | 35234 |
| 6 | -582958 |
| 7 | 10076354 |
| 8 | -179802046 |
| 9 | 3287029698 |
| 10 | -61246957902 |
| 11 | 1158889656930 |
| 12 | -22207636788894 |
| 13 | 430106644358242 |
| 14 | -8405699952109166 |
| 15 | 165557885912786818 |
| 16 | -3282954949273886590 |
| 17 | 65487784219460233602 |
| 18 | -1313225110482709157518 |