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 | -7 |
| 2 | 563 |
| 3 | -1197 |
| 4 | 86723 |
| 5 | -164787 |
| 6 | 74801381 |
| 7 | -18522777 |
| 8 | 1139843843 |
| 9 | -1951123167 |
| 10 | 1298700326833 |
| 11 | -187876029957 |
| 12 | 972149024030033 |
| 13 | -19896949323147 |
| 14 | 1350728831401523 |
| 15 | -897215933098737 |
| 16 | -1246115140314506189 |
| 17 | -721449189755468727 |
| 18 | 18942287537297864987519 |