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 | 1 |
| 2 | -5 |
| 3 | 37 |
| 4 | -413 |
| 5 | 6421 |
| 6 | -128285 |
| 7 | 3125557 |
| 8 | -89781053 |
| 9 | 2969440021 |
| 10 | -111109062365 |
| 11 | 4639580153077 |
| 12 | -213856576973693 |
| 13 | 10784605095793621 |
| 14 | -590598038062108445 |
| 15 | 34901993971832092597 |
| 16 | -2213771863243583654333 |
| 17 | 150004882482828402563221 |