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 | 1 |
| 1 | 2800 |
| 2 | 791256327456 |
| 3 | 63136448710941913967813221600 |
| 4 | 23917266934978072380933845882599985470951536677947182256755 |