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 | 0 |
| 2 | 2 |
| 3 | 13 |
| 4 | 53 |
| 5 | 810 |
| 6 | 20564 |
| 7 | 274904 |
| 8 | 6341424 |
| 9 | 419586990 |