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) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 1 |
| 5 | -1 |
| 6 | -2 |
| 7 | 0 |
| 8 | -10 |
| 9 | 29 |
| 10 | -689 |
| 11 | 79779 |
| 12 | -306741785 |
| 13 | -537059115735445 |
| 14 | 32782820784889194174016393 |
| 15 | 123899509182081496572342154385115870319926534 |
| 16 | 6620488215208352146569523585853411114659592927465468100410366988520167986216 |