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 | -3 |
| 3 | 28 |
| 4 | -255 |
| 5 | 2376 |
| 6 | -20195 |
| 7 | 71688 |
| 8 | 3834369 |
| 9 | -187855280 |
| 10 | 6676401501 |
| 11 | -220595216280 |
| 12 | 7180102389889 |
| 13 | -234023553073296 |
| 14 | 7631745228481725 |
| 15 | -245429882267144624 |
| 16 | 7501602903392006145 |
| 17 | -196609711096827812448 |
| 18 | 2542435002501531333949 |