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 | 4 |
| 3 | 7 |
| 4 | 272 |
| 5 | 211 |
| 6 | 51012 |
| 7 | 14197 |
| 8 | 18640960 |
| 9 | 1690981 |
| 10 | 11225320100 |
| 11 | 313968931 |
| 12 | 10079828372880 |
| 13 | 83828316391 |
| 14 | 12627774819845668 |
| 15 | 30436810578889 |
| 16 | 21046391759976988928 |
| 17 | 14425381885981321 |
| 18 | 45032132922921758270916 |
| 19 | 8649148282327007911 |
| 20 | 120314227994702795221920400 |