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 | 66 |
| 3 | 134 |
| 4 | 267 |
| 5 | 529 |
| 6 | 1048 |
| 7 | 2080 |
| 8 | 4137 |
| 9 | 8243 |
| 10 | 16446 |
| 11 | 32842 |
| 12 | 65623 |
| 13 | 131173 |
| 14 | 262260 |
| 15 | 524420 |
| 16 | 1048725 |
| 17 | 2097319 |
| 18 | 4194490 |
| 19 | 8388814 |
| 20 | 16777443 |
| 21 | 33554681 |
| 22 | 67109136 |
| 23 | 134218024 |
| 24 | 268435777 |
| 25 | 536871259 |
| 26 | 1073742198 |
| 27 | 2147484050 |
| 28 | 4294967727 |