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 | 2 |
| 6 | 7 |
| 7 | 24 |
| 8 | 81 |
| 9 | 274 |
| 10 | 923 |
| 11 | 3087 |
| 12 | 10232 |
| 13 | 33587 |
| 14 | 109190 |
| 15 | 351730 |
| 16 | 1123465 |
| 17 | 3561045 |
| 18 | 11210036 |
| 19 | 35073033 |
| 20 | 109137568 |
| 21 | 337969627 |
| 22 | 1042129366 |
| 23 | 3201226811 |
| 24 | 9800475386 |
| 25 | 29914121676 |
| 26 | 91063951213 |
| 27 | 276556071836 |
| 28 | 838101477953 |