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 | 2 |
| 2 | 6 |
| 3 | 52 |
| 4 | 3854 |
| 5 | 21090612 |
| 6 | 629815387162156 |
| 7 | 561871511512925116799625359336 |
| 8 | 446575758106416254441837050759254156476271759098752411181598 |