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 | 4 |
| 2 | 7 |
| 3 | 13 |
| 4 | 23 |
| 5 | 43 |
| 6 | 77 |
| 7 | 145 |
| 8 | 275 |
| 9 | 535 |
| 10 | 1053 |
| 11 | 2079 |
| 12 | 4133 |
| 13 | 8233 |
| 14 | 16427 |
| 15 | 32815 |
| 16 | 65589 |
| 17 | 131131 |
| 18 | 262205 |
| 19 | 524355 |
| 20 | 1048647 |
| 21 | 2097225 |
| 22 | 4194383 |
| 23 | 8388691 |
| 24 | 16777305 |
| 25 | 33554529 |
| 26 | 67108965 |
| 27 | 134217831 |
| 28 | 268435563 |
| 29 | 536871021 |
| 30 | 1073741937 |
| 31 | 2147483775 |
| 32 | 4294967427 |
| 33 | 8589934729 |