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 | -5 |
| 4 | -5 |
| 5 | 19 |
| 6 | 73 |
| 7 | -331 |
| 8 | -2795 |
| 9 | 18265 |
| 10 | 58643 |
| 11 | -141349 |
| 12 | -4197973 |
| 13 | 1035215 |
| 14 | 61269445 |
| 15 | -9158903 |
| 16 | -1495930487 |
| 17 | -34376687 |
| 18 | 26949145375 |
| 19 | 33594289475 |
| 20 | -1013112936505 |
| 21 | -4905856636525 |
| 22 | 459074207581145 |
| 23 | 1713253866399725 |
| 24 | -6497000065206625 |
| 25 | -51270656805872335 |
| 26 | 239235470859971731 |