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) |
|---|---|
| 1 | 0 |
| 2 | 4320 |
| 3 | 61440 |
| 4 | -8810640 |
| 5 | -263208960 |
| 6 | 22737197280 |
| 7 | 1104970014720 |
| 8 | -61319781714960 |
| 9 | -4559126871265280 |
| 10 | 157589681950830816 |
| 11 | 18460588655551795200 |
| 12 | -337394373951169867920 |
| 13 | -73200715363477357608960 |
| 14 | 306095068890572836888800 |
| 15 | 283363485933298319434493952 |
| 16 | 2600519516007145850005282800 |