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 | 0 |
| 1 | 1 |
| 2 | 1 |
| 3 | 11 |
| 4 | 13 |
| 5 | 57 |
| 6 | 15 |
| 7 | 247 |
| 8 | 251 |
| 9 | 1013 |
| 10 | 509 |
| 11 | 4083 |
| 12 | 4089 |
| 13 | 16369 |
| 14 | 2047 |
| 15 | 65519 |
| 16 | 65527 |
| 17 | 262125 |
| 18 | 131067 |
| 19 | 1048555 |
| 20 | 1048565 |
| 21 | 4194281 |
| 22 | 1048573 |
| 23 | 16777191 |
| 24 | 16777203 |
| 25 | 67108837 |
| 26 | 33554425 |
| 27 | 268435427 |
| 28 | 268435441 |
| 29 | 1073741793 |
| 30 | 67108863 |
| 31 | 4294967263 |
| 32 | 4294967279 |
| 33 | 17179869149 |