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 | 6 |
| 2 | -4 |
| 3 | 16 |
| 4 | -24 |
| 5 | 56 |
| 6 | -104 |
| 7 | 216 |
| 8 | -424 |
| 9 | 856 |
| 10 | -1704 |
| 11 | 3416 |
| 12 | -6824 |
| 13 | 13656 |
| 14 | -27304 |
| 15 | 54616 |
| 16 | -109224 |
| 17 | 218456 |
| 18 | -436904 |
| 19 | 873816 |
| 20 | -1747624 |
| 21 | 3495256 |
| 22 | -6990504 |
| 23 | 13981016 |
| 24 | -27962024 |
| 25 | 55924056 |
| 26 | -111848104 |
| 27 | 223696216 |
| 28 | -447392424 |
| 29 | 894784856 |
| 30 | -1789569704 |
| 31 | 3579139416 |
| 32 | -7158278824 |