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) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 25 |
| 3 | 3360 |
| 4 | 1336336 |
| 5 | 1158917760 |
| 6 | 1870414552161 |
| 7 | 5024209998931200 |
| 8 | 20882706457600000000 |
| 9 | 126806525870641017811200 |
| 10 | 1078732544346879404306640625 |
| 11 | 12413512011036114072165367296000 |
| 12 | 188031682201497672618081000000000000 |
| 13 | 3661653518107730704646938085472357120000 |