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) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 19 |
| 3 | 7 |
| 4 | 449 |
| 5 | 31 |
| 6 | 2647 |
| 7 | 127 |
| 8 | 7649 |
| 9 | 511 |
| 10 | 67523 |
| 11 | 2047 |
| 12 | 11178659 |
| 13 | 8191 |
| 14 | 98305 |
| 15 | 32767 |
| 16 | 33419233 |
| 17 | 131071 |
| 18 | 209233981 |
| 19 | 524287 |
| 20 | 345855139 |
| 21 | 2097151 |
| 22 | 579668327 |
| 23 | 8388607 |
| 24 | 45565432859 |
| 25 | 33554431 |
| 26 | 411206281 |
| 27 | 134217727 |
| 28 | 209789384821 |
| 29 | 536870911 |
| 30 | 23993971665011 |
| 31 | 2147483647 |
| 32 | -5518887720767 |