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 | 14 |
| 4 | -86 |
| 5 | 955 |
| 6 | -11851 |
| 7 | 183800 |
| 8 | -3273914 |
| 9 | 67643293 |
| 10 | -1571615577 |
| 11 | 40838683608 |
| 12 | -1170198385960 |
| 13 | 36717193651461 |
| 14 | -1251181160936837 |
| 15 | 46033142685018824 |
| 16 | -1818354391006060750 |
| 17 | 76762360864947676457 |
| 18 | -3448789505696369210193 |