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) |
|---|---|
| 3 | 1 |
| 4 | 4 |
| 5 | 14 |
| 6 | 44 |
| 7 | 133 |
| 8 | 392 |
| 9 | 1140 |
| 10 | 3288 |
| 11 | 9438 |
| 12 | 27016 |
| 13 | 77220 |
| 14 | 220584 |
| 15 | 630084 |
| 16 | 1800384 |
| 17 | 5147328 |
| 18 | 14727168 |
| 19 | 42171849 |
| 20 | 120870324 |
| 21 | 346757334 |
| 22 | 995742748 |
| 23 | 2862099185 |
| 24 | 8234447672 |
| 25 | 23713180780 |
| 26 | 68350541480 |
| 27 | 197188167735 |
| 28 | 569371325796 |