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 | 0 |
| 2 | -7 |
| 3 | 64 |
| 4 | -527 |
| 5 | 3776 |
| 6 | -7199 |
| 7 | -712704 |
| 8 | 28545857 |
| 9 | -881543168 |
| 10 | 25615822601 |
| 11 | -733594255360 |
| 12 | 20859188600881 |
| 13 | -580152163418112 |
| 14 | 15048530008948913 |
| 15 | -311489672222081024 |
| 16 | 713562283940993281 |
| 17 | 511135051171610230784 |
| 18 | -48010258775057340355559 |
| 19 | 3439412411849176925601792 |