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 | -2 |
| 2 | 5 |
| 3 | -14 |
| 4 | 37 |
| 5 | -98 |
| 6 | 261 |
| 7 | -694 |
| 8 | 1845 |
| 9 | -4906 |
| 10 | 13045 |
| 11 | -34686 |
| 12 | 92229 |
| 13 | -245234 |
| 14 | 652069 |
| 15 | -1733830 |
| 16 | 4610197 |
| 17 | -12258362 |
| 18 | 32594581 |
| 19 | -86667918 |
| 20 | 230447141 |
| 21 | -612751362 |
| 22 | 1629285701 |
| 23 | -4332217046 |
| 24 | 11519222517 |
| 25 | -30629233482 |
| 26 | 81442123573 |
| 27 | -216551925662 |
| 28 | 575804441861 |
| 29 | -1531045056530 |