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 | 3 |
| 1 | -9 |
| 2 | 69 |
| 3 | -531 |
| 4 | 6147 |
| 5 | -73665 |
| 6 | 1143045 |
| 7 | -18456795 |
| 8 | 359420355 |
| 9 | -7279744185 |
| 10 | 170639259525 |
| 11 | -4151789871075 |
| 12 | 113815089771075 |
| 13 | -3231091019581425 |
| 14 | 101428235414230725 |
| 15 | -3289812808335928875 |
| 16 | 116369085609950047875 |
| 17 | -4244245621899589931625 |
| 18 | 167038144384492533277125 |