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 | 3 |
| 2 | 11 |
| 3 | 41 |
| 4 | 149 |
| 5 | 527 |
| 6 | 1823 |
| 7 | 6197 |
| 8 | 20777 |
| 9 | 68891 |
| 10 | 226355 |
| 11 | 738113 |
| 12 | 2391485 |
| 13 | 7705895 |
| 14 | 24712007 |
| 15 | 78918989 |
| 16 | 251105873 |
| 17 | 796364339 |
| 18 | 2518233179 |
| 19 | 7942120025 |
| 20 | 24988621541 |
| 21 | 78452649023 |
| 22 | 245818300271 |
| 23 | 768835960421 |
| 24 | 2400651060089 |