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 | 1 |
| 3 | 4 |
| 4 | 34 |
| 5 | 744 |
| 6 | 17585 |
| 7 | 688202 |
| 8 | 33248174 |
| 9 | 2144597292 |
| 10 | 169696358796 |
| 11 | 16521881847592 |