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 | 2 |
| 2 | 4 |
| 3 | 9 |
| 4 | 21 |
| 5 | 50 |
| 6 | 121 |
| 7 | 296 |
| 8 | 730 |
| 9 | 1812 |
| 10 | 4521 |
| 11 | 11328 |
| 12 | 28485 |
| 13 | 71844 |
| 14 | 181674 |
| 15 | 460443 |
| 16 | 1169283 |
| 17 | 2974574 |
| 18 | 7578937 |
| 19 | 19337489 |
| 20 | 49401526 |
| 21 | 126350742 |
| 22 | 323495259 |
| 23 | 829033334 |
| 24 | 2126454271 |
| 25 | 5458711430 |
| 26 | 14023219126 |
| 27 | 36049991901 |
| 28 | 92734505565 |