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) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 2 |
| 6 | 14 |
| 7 | 79 |
| 8 | 430 |
| 9 | 2161 |
| 10 | 10162 |
| 11 | 45282 |
| 12 | 192945 |
| 13 | 790849 |
| 14 | 3138808 |
| 15 | 12116550 |
| 16 | 45675153 |
| 17 | 168661704 |
| 18 | 611701138 |
| 19 | 2183635232 |
| 20 | 7686541342 |
| 21 | 26720976964 |
| 22 | 91856241351 |
| 23 | 312594121721 |
| 24 | 1054104924270 |