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 | 10 |
| 6 | 70 |
| 7 | 424 |
| 8 | 2382 |
| 9 | 12804 |
| 10 | 66946 |
| 11 | 343772 |
| 12 | 1744314 |
| 13 | 8780912 |
| 14 | 43976688 |
| 15 | 219546976 |
| 16 | 1094132461 |
| 17 | 5448766458 |
| 18 | 27135655714 |
| 19 | 135218356264 |
| 20 | 674461583180 |
| 21 | 3368432133000 |
| 22 | 16847360404260 |
| 23 | 84396523333080 |
| 24 | 423485559461250 |