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) |
|---|---|
| 1 | 0 |
| 2 | 1 |
| 3 | 0 |
| 4 | 4 |
| 5 | 3 |
| 6 | 18 |
| 7 | 30 |
| 8 | 98 |
| 9 | 219 |
| 10 | 596 |
| 11 | 1464 |
| 12 | 3783 |
| 13 | 9540 |
| 14 | 24328 |
| 15 | 61740 |
| 16 | 156985 |
| 17 | 398904 |
| 18 | 1013772 |
| 19 | 2576475 |
| 20 | 6547574 |
| 21 | 16640382 |
| 22 | 42288806 |
| 23 | 107473443 |
| 24 | 273129468 |
| 25 | 694130016 |
| 26 | 1764047839 |
| 27 | 4483130424 |
| 28 | 11393354512 |
| 29 | 28954911624 |
| 30 | 73585574049 |