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 | 3 |
| 7 | 1 |
| 8 | 6 |
| 9 | 9 |
| 10 | 30 |
| 11 | 51 |
| 12 | 198 |
| 13 | 470 |
| 14 | 1623 |
| 15 | 4830 |
| 16 | 16070 |
| 17 | 51948 |
| 18 | 175047 |
| 19 | 588120 |
| 20 | 2015226 |
| 21 | 6933048 |
| 22 | 24123941 |
| 23 | 84428820 |
| 24 | 297753519 |