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) |
|---|---|
| 5 | 1 |
| 6 | 3 |
| 7 | 9 |
| 8 | 31 |
| 9 | 105 |
| 10 | 355 |
| 11 | 1197 |
| 12 | 4011 |
| 13 | 13329 |
| 14 | 43883 |
| 15 | 143105 |
| 16 | 462391 |
| 17 | 1481229 |
| 18 | 4707743 |
| 19 | 14856441 |
| 20 | 46585671 |
| 21 | 145253757 |
| 22 | 450624055 |
| 23 | 1391743825 |
| 24 | 4281348119 |
| 25 | 13124142489 |
| 26 | 40105164499 |
| 27 | 122213161617 |
| 28 | 371496978671 |
| 29 | 1126750503081 |