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 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 10 |
| 5 | 26 |
| 6 | 74 |
| 7 | 218 |
| 8 | 672 |
| 9 | 2134 |
| 10 | 6964 |
| 11 | 23206 |
| 12 | 78724 |
| 13 | 271014 |
| 14 | 944766 |
| 15 | 3328872 |
| 16 | 11838378 |
| 17 | 42441326 |
| 18 | 153236900 |
| 19 | 556746772 |
| 20 | 2034098988 |