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 | 4 |
| 2 | -24 |
| 3 | -800 |
| 4 | 9824 |
| 5 | 381824 |
| 6 | -5715712 |
| 7 | -236348416 |
| 8 | 3885237760 |
| 9 | 166141515776 |
| 10 | -2884493168640 |
| 11 | -125973507063808 |
| 12 | 2266868356071424 |
| 13 | 100441740460359680 |
| 14 | -1853741093854511104 |
| 15 | -83006642599731134464 |
| 16 | 1561071322451916750848 |
| 17 | 70464426394180291919872 |