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 | 7 |
| 4 | 17 |
| 5 | 19 |
| 6 | 31 |
| 7 | 67 |
| 8 | 79 |
| 9 | 127 |
| 10 | 4099 |
| 11 | 4111 |
| 12 | 4159 |
| 13 | 8191 |
| 14 | 65537 |
| 15 | 65539 |
| 16 | 65551 |
| 17 | 65599 |
| 18 | 131071 |
| 19 | 262147 |
| 20 | 266239 |
| 21 | 524287 |
| 22 | 1073741827 |
| 23 | 1073741839 |
| 24 | 1073807359 |
| 25 | 2147483647 |
| 26 | 2305843009213693951 |
| 27 | 309485009821345068724785151 |