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 | -11 |
| 3 | 3 |
| 4 | 91 |
| 5 | -43 |
| 6 | -12347 |
| 7 | 1183 |
| 8 | 62851 |
| 9 | -54423 |
| 10 | -39448591 |
| 11 | 3799763 |
| 12 | 27287144401 |
| 13 | -375591203 |
| 14 | -34562009741 |
| 15 | 49954996743 |
| 16 | 89299092717107 |
| 17 | -8604866798383 |
| 18 | -135379643536733633 |
| 19 | 1863607913992123 |
| 20 | 2694379428323830241 |
| 21 | -495661415843787963 |
| 22 | -1648224141847799919403 |