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 | 1 |
| 2 | 257 |
| 3 | 6562 |
| 4 | 65537 |
| 5 | 390626 |
| 6 | 1686434 |
| 7 | 5764802 |
| 8 | 16777217 |
| 9 | 43046722 |
| 10 | 100390882 |
| 11 | 214358882 |
| 12 | 430053794 |
| 13 | 815730722 |
| 14 | 1481554114 |
| 15 | 2563287812 |
| 16 | 4294967297 |
| 17 | 6975757442 |
| 18 | 11063007554 |
| 19 | 16983563042 |
| 20 | 25600456162 |
| 21 | 37828630724 |