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 | 2 |
| 1 | 6 |
| 2 | 90 |
| 3 | 47250 |
| 4 | 66852843750 |
| 5 | 2806877704512541816406250 |
| 6 | 1216935896582703898519354781702537118597533386230468750 |