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 | 51 |
| 6 | 126 |
| 7 | 318 |
| 8 | 812 |
| 9 | 2100 |
| 10 | 5482 |
| 11 | 14438 |
| 12 | 38303 |
| 13 | 102302 |
| 14 | 274824 |
| 15 | 742210 |
| 16 | 2013941 |
| 17 | 5488239 |
| 18 | 15014376 |
| 19 | 41221775 |
| 20 | 113542455 |
| 21 | 313681756 |
| 22 | 868994723 |
| 23 | 2413526848 |
| 24 | 6719132105 |
| 25 | 18746838609 |
| 26 | 52412080624 |
| 27 | 146812972155 |
| 28 | 411977724704 |
| 29 | 1158006098132 |