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 | 3 |
| 4 | 2 |
| 5 | 3 |
| 6 | 4 |
| 7 | 1 |
| 8 | -6 |
| 9 | 45 |
| 10 | -86 |
| 11 | 173 |
| 12 | -100 |
| 13 | 2641 |
| 14 | -48311 |
| 15 | 717766 |
| 16 | -15527527 |
| 17 | 395694683 |
| 18 | -11210796201 |
| 19 | 356923346235 |
| 20 | -12694851400717 |
| 21 | 501010779605741 |
| 22 | -21827969798073020 |
| 23 | 1044997258445975691 |
| 24 | -54740156237911040100 |