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 | 49 |
| 3 | -485 |
| 4 | 4801 |
| 5 | -47525 |
| 6 | 470449 |
| 7 | -4656965 |
| 8 | 46099201 |
| 9 | -456335045 |
| 10 | 4517251249 |
| 11 | -44716177445 |
| 12 | 442644523201 |
| 13 | -4381729054565 |
| 14 | 43374646022449 |
| 15 | -429364731169925 |
| 16 | 4250272665676801 |
| 17 | -42073361925598085 |
| 18 | 416483346590304049 |