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 | 3 |
| 3 | 7 |
| 4 | 15 |
| 5 | 31 |
| 6 | 21 |
| 7 | 127 |
| 8 | 945 |
| 9 | 4095 |
| 10 | 1023 |
| 11 | 544635 |
| 12 | 46035 |
| 13 | 8191 |
| 14 | 355725 |
| 15 | 279279 |
| 16 | 1796165 |
| 17 | 5388495 |
| 18 | 180213 |
| 19 | 131071 |
| 20 | 110800305 |
| 21 | 249987465 |
| 22 | 42833475 |
| 23 | 3112865 |
| 24 | 8109585 |
| 25 | 524287 |
| 26 | 9338595 |
| 27 | 49198149 |
| 28 | 253255275 |
| 29 | 22017975903 |
| 30 | 13341660255 |
| 31 | 30101431815 |
| 32 | 709933138551 |