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) |
|---|---|
| 4 | 561 |
| 5 | 4435201 |
| 6 | 691891201 |
| 7 | 39520825344001 |
| 8 | 13516122267648001 |
| 9 | 2872446304320552960001 |
| 10 | 982417999304411328282624000001 |
| 11 | 913648739353102535302840320000001 |