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 | -7 |
| 3 | -239 |
| 4 | 30185 |
| 5 | 15518977 |
| 6 | -31752293287 |
| 7 | -260178568173071 |
| 8 | 8525011498792301513 |
| 9 | 1117407361630407158712289 |
| 10 | -585841036144574163016069731271 |
| 11 | -1228598872333737909217248906305521967 |
| 12 | 10306231872061986643099600924851012311829929 |