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) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 9 |
| 3 | 32 |
| 4 | 126 |
| 5 | 538 |
| 6 | 2429 |
| 7 | 11412 |
| 8 | 55201 |
| 9 | 272993 |
| 10 | 1373784 |
| 11 | 7011297 |
| 12 | 36201841 |
| 13 | 188761743 |
| 14 | 992491049 |
| 15 | 5256244537 |
| 16 | 28013213196 |
| 17 | 150128293038 |
| 18 | 808543940999 |
| 19 | 4373798584407 |
| 20 | 23753913152691 |
| 21 | 129469596050953 |
| 22 | 707969244301884 |
| 23 | 3882857013894482 |
| 24 | 21353585584100401 |