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 | 0 |
| 2 | 4 |
| 3 | 6 |
| 4 | 13 |
| 5 | 15 |
| 6 | 27 |
| 7 | 47 |
| 8 | 55 |
| 9 | 111 |
| 10 | 223 |
| 11 | 447 |
| 12 | 895 |
| 13 | 1791 |
| 14 | 3583 |
| 15 | 7167 |
| 16 | 14335 |
| 17 | 28671 |
| 18 | 57343 |
| 19 | 114687 |
| 20 | 229375 |
| 21 | 458751 |
| 22 | 917503 |
| 23 | 1835007 |
| 24 | 3670015 |
| 25 | 7340031 |
| 26 | 14680063 |
| 27 | 29360127 |
| 28 | 58720255 |
| 29 | 117440511 |