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 | 1 |
| 3 | 3 |
| 4 | 19 |
| 5 | 391 |
| 6 | 25532 |
| 7 | 5539434 |
| 8 | 4116036800 |
| 9 | 10694128575819 |
| 10 | 98630958757213465 |
| 11 | 3267417937114919996252 |