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 | 5 |
| 3 | 9 |
| 4 | 17 |
| 5 | 37 |
| 6 | 81 |
| 7 | 197 |
| 8 | 477 |
| 9 | 1197 |
| 10 | 3077 |
| 11 | 7989 |
| 12 | 20649 |
| 13 | 53885 |
| 14 | 140601 |
| 15 | 366917 |
| 16 | 959685 |
| 17 | 2511477 |
| 18 | 6571681 |
| 19 | 17202449 |
| 20 | 45027677 |
| 21 | 117871345 |
| 22 | 308581637 |
| 23 | 807852685 |
| 24 | 2114904397 |
| 25 | 5536838045 |
| 26 | 14495554593 |
| 27 | 37949503089 |
| 28 | 99352690141 |
| 29 | 260108204933 |