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 | 1 |
| 4 | -2 |
| 5 | 3 |
| 6 | -9 |
| 7 | 9 |
| 8 | -71 |
| 9 | -96 |
| 10 | -1325 |
| 11 | -6843 |
| 12 | -54922 |
| 13 | -417975 |
| 14 | -3586117 |
| 15 | -32531983 |
| 16 | -316599861 |
| 17 | -3274076017 |
| 18 | -35914014266 |
| 19 | -416386323306 |
| 20 | -5088908019824 |
| 21 | -65392831090975 |
| 22 | -881473287321301 |
| 23 | -12437647407521019 |
| 24 | -183345613125389337 |