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 | 0 |
| 2 | 0 |
| 3 | -2 |
| 4 | -2 |
| 5 | -2 |
| 6 | 2 |
| 7 | 6 |
| 8 | 10 |
| 9 | 6 |
| 10 | -6 |
| 11 | -26 |
| 12 | -38 |
| 13 | -26 |
| 14 | 26 |
| 15 | 102 |
| 16 | 154 |
| 17 | 102 |
| 18 | -102 |
| 19 | -410 |
| 20 | -614 |
| 21 | -410 |
| 22 | 410 |
| 23 | 1638 |
| 24 | 2458 |
| 25 | 1638 |
| 26 | -1638 |
| 27 | -6554 |
| 28 | -9830 |
| 29 | -6554 |
| 30 | 6554 |
| 31 | 26214 |
| 32 | 39322 |
| 33 | 26214 |
| 34 | -26214 |
| 35 | -104858 |
| 36 | -157286 |
| 37 | -104858 |
| 38 | 104858 |
| 39 | 419430 |
| 40 | 629146 |
| 41 | 419430 |
| 42 | -419430 |
| 43 | -1677722 |
| 44 | -2516582 |
| 45 | -1677722 |
| 46 | 1677722 |