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 | 2 |
| 2 | 4 |
| 3 | 12 |
| 4 | 72 |
| 5 | 864 |
| 6 | 20736 |
| 7 | 933120 |
| 8 | 117573120 |
| 9 | 42326323200 |
| 10 | 36315985305600 |
| 11 | 146426052752179200 |
| 12 | 1475974611741966336000 |
| 13 | 37784950060594338201600000 |
| 14 | 2031318915257551621718016000000 |
| 15 | 212719716805770805826310635520000000 |