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 | 114689 |
| 8 | 274177 |
| 9 | 319489 |
| 10 | 974849 |
| 11 | 2424833 |
| 12 | 6700417 |
| 13 | 13631489 |
| 14 | 26017793 |
| 15 | 45592577 |
| 16 | 63766529 |
| 17 | 167772161 |
| 18 | 825753601 |
| 19 | 1214251009 |
| 20 | 6487031809 |
| 21 | 70525124609 |
| 22 | 190274191361 |
| 23 | 646730219521 |
| 24 | 2710954639361 |
| 25 | 2748779069441 |
| 26 | 4485296422913 |
| 27 | 6597069766657 |