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 | 1 |
| 3 | 3 |
| 4 | 3 |
| 5 | 5 |
| 6 | 900 |
| 7 | 756000 |
| 8 | 15876000 |
| 9 | 42674688000 |
| 10 | 56899584000 |
| 11 | 1204450394112000 |
| 12 | 2782280410398720000 |
| 13 | 154249625952505036800000 |
| 14 | 61082851877191994572800000 |