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 | 3 |
| 3 | 3 |
| 4 | 6 |
| 5 | 12 |
| 6 | 60 |
| 7 | 660 |
| 8 | 38940 |
| 9 | 25661460 |
| 10 | 999231590940 |
| 11 | 25641740502411581460 |
| 12 | 25622037156669717708454796390940 |
| 13 | 656993627914472375437286314449293585586011019581460 |