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 | 5 |
| 4 | 9 |
| 5 | 30 |
| 6 | 68 |
| 7 | 195 |
| 8 | 483 |
| 9 | 1309 |
| 10 | 3355 |
| 11 | 8900 |
| 12 | 23112 |
| 13 | 60813 |
| 14 | 158717 |
| 15 | 416325 |
| 16 | 1088661 |
| 17 | 2852242 |
| 18 | 7463884 |
| 19 | 19546175 |
| 20 | 51163695 |
| 21 | 133962621 |
| 22 | 350695511 |
| 23 | 918170280 |
| 24 | 2403740304 |
| 25 | 6293172025 |
| 26 | 16475579353 |
| 27 | 43133883845 |
| 28 | 112925557953 |