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 | 8 |
| 2 | 36 |
| 3 | 120 |
| 4 | 330 |
| 5 | 792 |
| 6 | 1716 |
| 7 | 3432 |
| 8 | 6434 |
| 9 | 11424 |
| 10 | 19312 |
| 11 | 31008 |
| 12 | 46512 |
| 13 | 62016 |
| 14 | 62016 |
| 15 | 0 |
| 16 | -245156 |
| 17 | -961376 |
| 18 | -2787760 |
| 19 | -7065760 |
| 20 | -16478280 |
| 21 | -36159840 |
| 22 | -75522960 |
| 23 | -151045920 |
| 24 | -290021896 |
| 25 | -534308096 |
| 26 | -940325760 |
| 27 | -1564496128 |
| 28 | -2406819200 |
| 29 | -3249142272 |
| 30 | -3249142272 |