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 | 0 |
| 2 | 3 |
| 3 | 104 |
| 4 | 5355 |
| 5 | 15107664 |
| 6 | 2684295425 |
| 7 | 2261529015616800 |
| 8 | 97901171532649325295 |
| 9 | 671549787473885210310580160 |
| 10 | 113480471243172592617657936025689 |
| 11 | 67423693602852027222491606156048516615143200 |
| 12 | 52627558956534012662100374980910169826998422190695 |