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) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 3 |
| 4 | 24 |
| 5 | 50 |
| 6 | 1800 |
| 7 | 5145 |
| 8 | 878080 |
| 9 | 3429216 |
| 10 | 2857680000 |
| 11 | 15219319500 |
| 12 | 63117561830400 |
| 13 | 457937132487120 |
| 14 | 9577928124440387712 |
| 15 | 94609025993497640625 |
| 16 | 10077943267571584204800000 |