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 | 0 |
| 1 | 0 |
| 2 | 2 |
| 3 | 24 |
| 4 | 384 |
| 5 | 7680 |
| 6 | 184320 |
| 7 | 5160960 |
| 8 | 165150720 |
| 9 | 5945425920 |
| 10 | 237817036800 |
| 11 | 10463949619200 |
| 12 | 502269581721600 |
| 13 | 26118018249523200 |
| 14 | 1462609021973299200 |
| 15 | 87756541318397952000 |
| 16 | 5616418644377468928000 |