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) |
|---|---|
| 3 | 1 |
| 4 | -455 |
| 5 | 236665 |
| 6 | -120935815 |
| 7 | 61934287481 |
| 8 | -31709385606535 |
| 9 | 16235267484138105 |
| 10 | -8312452980450674055 |
| 11 | 4255976180162154314361 |
| 12 | -2179059787976052939572615 |
| 13 | 1115678612484825190455949945 |
| 14 | -571227449525600988055816521095 |