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 | 3 |
| 2 | 5 |
| 3 | 17 |
| 4 | 257 |
| 5 | 641 |
| 6 | 65537 |
| 7 | 274177 |
| 8 | 6700417 |
| 9 | 67280421310721 |