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 | -11 |
| 4 | -19 |
| 5 | -654 |
| 6 | 6439 |
| 7 | -103298 |
| 8 | -233543 |
| 9 | -479042 |
| 10 | 999089891 |
| 11 | -23581102192 |
| 12 | -56760341915 |
| 13 | -23425343599215 |
| 14 | 736752260240319 |
| 15 | 31008836538146011 |
| 16 | 76278687880642289 |
| 17 | -48483493990740616866 |
| 18 | -121045054967668089989 |
| 19 | -104414952870932959886007 |