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 | 1 |
| 3 | 1 |
| 4 | -281 |
| 5 | -5221 |
| 6 | 5459 |
| 7 | 91207079 |
| 8 | -2650986803 |
| 9 | -6171801683 |
| 10 | 4283933145517 |
| 11 | 11963983648109 |
| 12 | -208697624924077 |
| 13 | -29320119130515566117 |
| 14 | 2700231121460756431181 |
| 15 | 10084288256532215186381 |
| 16 | -6782242429223267933535073 |
| 17 | -51748587106835353426330148693 |