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 | 2 |
| 3 | 4 |
| 4 | 12 |
| 5 | 240 |
| 6 | 40200 |
| 7 | 1385211600 |
| 8 | 1469089808430082650 |
| 9 | 1705264091048404496800363077779646800 |
| 10 | 2355419752377504356995163180927294204575594409432081035253034399529376520 |