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) |
|---|---|
| 2 | 1 |
| 3 | 3 |
| 4 | 9 |
| 5 | 27 |
| 6 | 77 |
| 7 | 215 |
| 8 | 597 |
| 9 | 1655 |
| 10 | 4593 |
| 11 | 12775 |
| 12 | 35629 |
| 13 | 99651 |
| 14 | 279501 |
| 15 | 786071 |
| 16 | 2216437 |
| 17 | 6264663 |
| 18 | 17746897 |
| 19 | 50380895 |
| 20 | 143307269 |
| 21 | 408388819 |
| 22 | 1165819757 |
| 23 | 3333448075 |
| 24 | 9545909641 |
| 25 | 27375525727 |
| 26 | 78612676241 |
| 27 | 226034151539 |
| 28 | 650692800633 |