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 | 8 |
| 3 | 900 |
| 4 | 366336 |
| 5 | 378028800 |
| 6 | 833156928000 |
| 7 | 3477528928742400 |
| 8 | 25183876050321408000 |
| 9 | 296058177312000019660800 |
| 10 | 5362158372805111867637760000 |
| 11 | 143458227395428379364635443200000 |