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 | 8 |
| 1 | -6 |
| 2 | 12 |
| 3 | -25 |
| 4 | 52 |
| 5 | -106 |
| 6 | 212 |
| 7 | -420 |
| 8 | 832 |
| 9 | -1656 |
| 10 | 3312 |
| 11 | -6640 |
| 12 | 13312 |
| 13 | -26656 |
| 14 | 53312 |
| 15 | -106560 |
| 16 | 212992 |
| 17 | -425856 |
| 18 | 851712 |
| 19 | -1703680 |
| 20 | 3407872 |
| 21 | -6816256 |
| 22 | 13632512 |
| 23 | -27264000 |
| 24 | 54525952 |
| 25 | -109049856 |
| 26 | 218099712 |
| 27 | -436203520 |
| 28 | 872415232 |
| 29 | -1744838656 |
| 30 | 3489677312 |
| 31 | -6979338240 |