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 | 3 |
| 2 | 7 |
| 3 | 31 |
| 4 | 43 |
| 5 | 127 |
| 6 | 241 |
| 7 | 967 |
| 8 | 5323 |
| 9 | 8191 |
| 10 | 117127 |
| 11 | 131071 |
| 12 | 524287 |
| 13 | 7496191 |
| 14 | 10307263 |
| 15 | 77948683 |
| 16 | 253755391 |
| 17 | 428717761 |
| 18 | 738197503 |
| 19 | 1714871047 |
| 20 | 2147483647 |
| 21 | 16240345087 |
| 22 | 27437936767 |
| 23 | 42218553343 |
| 24 | 1965081755647 |
| 25 | 2414538435583 |
| 26 | 7024111812607 |
| 27 | 7860327022591 |
| 28 | 16630113370111 |