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 | 31 |
| 2 | 127 |
| 3 | 1093 |
| 4 | 2801 |
| 5 | 8191 |
| 6 | 19531 |
| 7 | 30941 |
| 8 | 131071 |
| 9 | 88741 |
| 10 | 524287 |
| 11 | 292561 |
| 12 | 797161 |
| 13 | 732541 |
| 14 | 3500201 |
| 15 | 5229043 |
| 16 | 12207031 |
| 17 | 25646167 |
| 18 | 28792661 |
| 19 | 39449441 |
| 20 | 48037081 |
| 21 | 305175781 |
| 22 | 262209281 |
| 23 | 917087137 |
| 24 | 2147483647 |
| 25 | 1394714501 |
| 26 | 2666986681 |