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 | 3 |
| 1 | 2 |
| 2 | 3 |
| 3 | 6 |
| 4 | 14 |
| 5 | 36 |
| 6 | 99 |
| 7 | 286 |
| 8 | 858 |
| 9 | 2652 |
| 10 | 8398 |
| 11 | 27132 |
| 12 | 89148 |
| 13 | 297160 |
| 14 | 1002915 |
| 15 | 3421710 |
| 16 | 11785890 |
| 17 | 40940460 |
| 18 | 143291610 |
| 19 | 504932340 |
| 20 | 1790214660 |
| 21 | 6382504440 |
| 22 | 22870640910 |
| 23 | 82334307276 |
| 24 | 297670187844 |
| 25 | 1080432533656 |
| 26 | 3935861372604 |
| 27 | 14386251913656 |
| 28 | 52749590350072 |