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 | 2 |
| 2 | 12 |
| 3 | 720 |
| 4 | 907200 |
| 5 | 251475840000 |
| 6 | 14272938808128000000 |
| 7 | 1683176415906545239680000000000 |
| 8 | 216212806227686567939021962996416000000000000 |