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 | 362880 |
| 2 | 12504636144000 |
| 3 | 1080491954750208000000 |
| 4 | 140810154080474667338550000000 |
| 5 | 23183587808948692737291767860055162880 |
| 6 | 4439413043841128802009762476941510771390464000 |