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 | 5 |
| 2 | -7 |
| 3 | -355 |
| 4 | -1103 |
| 5 | 39925 |
| 6 | 376105 |
| 7 | -5785075 |
| 8 | -113172895 |
| 9 | 915114725 |
| 10 | 37169367385 |
| 11 | -106989875075 |
| 12 | -13618566694895 |
| 13 | -27008721445675 |
| 14 | 5530280137847945 |
| 15 | 39751307896902125 |
| 16 | -2455777926682502975 |
| 17 | -32631559276626402875 |
| 18 | 1172785395732149604025 |