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 | 1 |
| 3 | 1 |
| 4 | 3 |
| 5 | 7 |
| 6 | 22 |
| 7 | 67 |
| 8 | 215 |
| 9 | 692 |
| 10 | 2283 |
| 11 | 7599 |
| 12 | 25631 |
| 13 | 87211 |
| 14 | 299386 |
| 15 | 1035059 |
| 16 | 3602083 |
| 17 | 12606318 |
| 18 | 44344764 |
| 19 | 156698081 |
| 20 | 555989604 |
| 21 | 1980050697 |
| 22 | 7075365521 |
| 23 | 25360341963 |
| 24 | 91155701023 |
| 25 | 328500571740 |
| 26 | 1186656421109 |
| 27 | 4296084607302 |