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 | 3 |
| 2 | 26 |
| 3 | 684 |
| 4 | 35664 |
| 5 | 3068640 |
| 6 | 392722560 |
| 7 | 69878833920 |
| 8 | 16484477184000 |
| 9 | 4976250951168000 |
| 10 | 1870345490614272000 |
| 11 | 856314330237628416000 |
| 12 | 469109144339151224832000 |
| 13 | 302956190548293037916160000 |