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) |
|---|---|
| 10 | 1 |
| 11 | 2 |
| 12 | 4 |
| 13 | 15 |
| 14 | 42 |
| 15 | 135 |
| 16 | 440 |
| 17 | 1480 |
| 18 | 5106 |
| 19 | 17890 |
| 20 | 63264 |
| 21 | 226018 |
| 22 | 812354 |
| 23 | 2936837 |
| 24 | 10666188 |
| 25 | 38901190 |
| 26 | 142386358 |