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 | 6 |
| 3 | 24 |
| 4 | 120 |
| 5 | 720 |
| 6 | 5038 |
| 7 | 40260 |
| 8 | 361636 |
| 9 | 3606044 |
| 10 | 39517182 |
| 11 | 472002456 |
| 12 | 6102356222 |
| 13 | 84896359836 |
| 14 | 1264499036118 |
| 15 | 20075760897736 |
| 16 | 338430468325576 |
| 17 | 6037037185793372 |
| 18 | 113608224705704476 |
| 19 | 2249252806749536964 |