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 | 1 |
| 3 | -5 |
| 4 | -23 |
| 5 | -39 |
| 6 | 361 |
| 7 | 2675 |
| 8 | 3697 |
| 9 | -90575 |
| 10 | -741839 |
| 11 | 52779 |
| 12 | 48483865 |
| 13 | 358510985 |
| 14 | -1225182503 |
| 15 | -43006420829 |
| 16 | -239523048095 |
| 17 | 2745896185953 |
| 18 | 54532102774753 |
| 19 | 144304368441179 |
| 20 | -6547928921714999 |
| 21 | -88336890555248327 |
| 22 | 199686588300036553 |
| 23 | 18186115601328322515 |