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 | 0 |
| 1 | 1 |
| 2 | 1 |
| 3 | -28 |
| 4 | 272 |
| 5 | 10473 |
| 6 | -1204227 |
| 7 | 61879504 |
| 8 | 5542428184 |
| 9 | -2801375692615 |
| 10 | 597270865802225 |
| 11 | -6353098642040604 |
| 12 | -85053828910331125224 |
| 13 | 62048537484671306803057 |
| 14 | -23357096658814809538526243 |
| 15 | -10072546328972154349642665952 |