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 | 6 |
| 2 | 33 |
| 3 | 145 |
| 4 | 752 |
| 5 | 3747 |
| 6 | 18577 |
| 7 | 93150 |
| 8 | 464697 |
| 9 | 2320289 |
| 10 | 11591504 |
| 11 | 57880641 |
| 12 | 289072233 |
| 13 | 1443683308 |
| 14 | 7209863009 |
| 15 | 36007227773 |
| 16 | 179824937844 |
| 17 | 898069917949 |
| 18 | 4485086714025 |
| 19 | 22399136063860 |
| 20 | 111864365243177 |
| 21 | 558666033595587 |