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) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 4 |
| 3 | 13 |
| 4 | 67 |
| 5 | 229 |
| 6 | 229 |
| 7 | 958 |
| 8 | 958 |
| 9 | 7519 |
| 10 | 27202 |
| 11 | 27202 |
| 12 | 204349 |
| 13 | 1267231 |
| 14 | 1267231 |
| 15 | 10833169 |
| 16 | 39530983 |
| 17 | 125624425 |
| 18 | 125624425 |
| 19 | 125624425 |
| 20 | 1287885892 |
| 21 | 4774670293 |
| 22 | 15235023496 |
| 23 | 46616083105 |
| 24 | 140759261932 |
| 25 | 140759261932 |
| 26 | 988047871375 |
| 27 | 3529913699704 |
| 28 | 11155511184691 |