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 | 3 |
| 3 | 70 |
| 4 | 7200 |
| 5 | 3098760 |
| 6 | 5461682688 |
| 7 | 39119789090720 |
| 8 | 1134989202339225600 |
| 9 | 133147573896710665570432 |
| 10 | 63073498348368958240316325888 |
| 11 | 120514654247860687784734309977868800 |