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 | 0 |
| 1 | 1 |
| 2 | 3 |
| 3 | 7 |
| 4 | 18 |
| 5 | 48 |
| 6 | 126 |
| 7 | 329 |
| 8 | 861 |
| 9 | 2255 |
| 10 | 5904 |
| 11 | 15456 |
| 12 | 40464 |
| 13 | 105937 |
| 14 | 277347 |
| 15 | 726103 |
| 16 | 1900962 |
| 17 | 4976784 |
| 18 | 13029390 |
| 19 | 34111385 |
| 20 | 89304765 |
| 21 | 233802911 |
| 22 | 612103968 |
| 23 | 1602508992 |
| 24 | 4195423008 |
| 25 | 10983760033 |
| 26 | 28755857091 |
| 27 | 75283811239 |
| 28 | 197095576626 |