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 | 2 |
| 3 | 9 |
| 4 | 40 |
| 5 | 290 |
| 6 | 2529 |
| 7 | 26629 |
| 8 | 301289 |
| 9 | 3568048 |
| 10 | 43305326 |
| 11 | 534671742 |
| 12 | 6684869463 |