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 | 2 |
| 1 | 2 |
| 2 | 5 |
| 3 | 15 |
| 4 | 43 |
| 5 | 118 |
| 6 | 316 |
| 7 | 836 |
| 8 | 2199 |
| 9 | 5769 |
| 10 | 15117 |
| 11 | 39592 |
| 12 | 103670 |
| 13 | 271430 |
| 14 | 710633 |
| 15 | 1860483 |
| 16 | 4870831 |
| 17 | 12752026 |
| 18 | 33385264 |
| 19 | 87403784 |
| 20 | 228826107 |
| 21 | 599074557 |
| 22 | 1568397585 |
| 23 | 4106118220 |
| 24 | 10749957098 |
| 25 | 28143753098 |
| 26 | 73681302221 |
| 27 | 192900153591 |