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 | 2 |
| 3 | 2 |
| 4 | 4 |
| 5 | 8 |
| 6 | 18 |
| 7 | 42 |
| 8 | 102 |
| 9 | 254 |
| 10 | 646 |
| 11 | 1670 |
| 12 | 4376 |
| 13 | 11596 |
| 14 | 31022 |
| 15 | 83670 |
| 16 | 227268 |
| 17 | 621144 |
| 18 | 1706934 |
| 19 | 4713558 |
| 20 | 13072764 |
| 21 | 36398568 |
| 22 | 101704038 |
| 23 | 285095118 |
| 24 | 801526446 |
| 25 | 2259520830 |
| 26 | 6385455594 |
| 27 | 18086805002 |
| 28 | 51339636952 |
| 29 | 146015545604 |