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 | 1 |
| 2 | 0 |
| 3 | 2 |
| 4 | 8 |
| 5 | 32 |
| 6 | 156 |
| 7 | 871 |
| 8 | 5292 |
| 9 | 28702 |
| 10 | 154162 |
| 11 | 845532 |
| 12 | 4662014 |
| 13 | 25579463 |
| 14 | 140098348 |
| 15 | 767973001 |
| 16 | 4212065280 |
| 17 | 23097682805 |
| 18 | 126643657272 |
| 19 | 694390484065 |
| 20 | 3807499106946 |
| 21 | 20877386149018 |
| 22 | 114474503105178 |
| 23 | 627683328355315 |
| 24 | 3441701959286326 |
| 25 | 18871492466212538 |