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 | 2 |
| 5 | 6 |
| 6 | 20 |
| 7 | 40 |
| 8 | 106 |
| 9 | 304 |
| 10 | 731 |
| 11 | 1936 |
| 12 | 5769 |
| 13 | 14343 |
| 14 | 39583 |
| 15 | 117957 |
| 16 | 305576 |
| 17 | 855474 |
| 18 | 2565922 |
| 19 | 6793516 |
| 20 | 19242857 |
| 21 | 57827068 |
| 22 | 155681341 |
| 23 | 444461623 |
| 24 | 1337436721 |
| 25 | 3645877447 |
| 26 | 10471728930 |
| 27 | 31534868169 |
| 28 | 86818242806 |
| 29 | 250543852080 |
| 30 | 754851821246 |
| 31 | 2094887707000 |