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 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 1 |
| 6 | 3 |
| 7 | 16 |
| 8 | 85 |
| 9 | 434 |
| 10 | 2270 |
| 11 | 11530 |
| 12 | 58397 |
| 13 | 290689 |
| 14 | 1436669 |
| 15 | 7036417 |
| 16 | 34286379 |
| 17 | 166316979 |
| 18 | 804556969 |
| 19 | 3884248150 |
| 20 | 18731031687 |
| 21 | 90269841908 |
| 22 | 434955103451 |
| 23 | 2096028083116 |
| 24 | 10104206843502 |