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 | -32 |
| 2 | 496 |
| 3 | -4992 |
| 4 | 36984 |
| 5 | -217280 |
| 6 | 1066432 |
| 7 | -4548352 |
| 8 | 17369116 |
| 9 | -60711456 |
| 10 | 197327712 |
| 11 | -603261056 |
| 12 | 1749861312 |
| 13 | -4849210560 |
| 14 | 12909347456 |
| 15 | -33162318080 |
| 16 | 82507571334 |
| 17 | -199432268416 |
| 18 | 469559849680 |
| 19 | -1079335967872 |