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) |
|---|---|
| 4 | 1 |
| 5 | 0 |
| 6 | 1 |
| 7 | 1 |
| 8 | 4 |
| 9 | 10 |
| 10 | 53 |
| 11 | 292 |
| 12 | 2224 |
| 13 | 18493 |
| 14 | 167504 |
| 15 | 1571020 |
| 16 | 15151289 |
| 17 | 148864939 |
| 18 | 1485904672 |
| 19 | 15028654628 |
| 20 | 153781899708 |
| 21 | 1589921572902 |
| 22 | 16591187039082 |