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 | 0 |
| 1 | 1 |
| 2 | 8 |
| 3 | 108 |
| 4 | 2304 |
| 5 | 72000 |
| 6 | 3110400 |
| 7 | 177811200 |
| 8 | 13005619200 |
| 9 | 1185137049600 |
| 10 | 131681894400000 |
| 11 | 17526860144640000 |
| 12 | 2753310393630720000 |
| 13 | 504085244567224320000 |