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 | 8 |
| 3 | 21 |
| 4 | 54 |
| 5 | 137 |
| 6 | 342 |
| 7 | 837 |
| 8 | 2006 |
| 9 | 4713 |
| 10 | 10882 |
| 11 | 24771 |
| 12 | 55764 |
| 13 | 124465 |
| 14 | 275934 |
| 15 | 608283 |
| 16 | 1334120 |
| 17 | 2911871 |
| 18 | 6325092 |
| 19 | 13674121 |
| 20 | 29425308 |
| 21 | 63042233 |
| 22 | 134517426 |
| 23 | 285984131 |
| 24 | 606056546 |
| 25 | 1280778343 |
| 26 | 2700105566 |
| 27 | 5680099085 |
| 28 | 11925792492 |
| 29 | 24993841655 |
| 30 | 52291456452 |