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 | 0 |
| 1 | 1 |
| 2 | 5 |
| 3 | 20 |
| 4 | 70 |
| 5 | 221 |
| 6 | 646 |
| 7 | 1772 |
| 8 | 4614 |
| 9 | 11490 |
| 10 | 27537 |
| 11 | 63808 |
| 12 | 143514 |
| 13 | 314279 |
| 14 | 671872 |
| 15 | 1405260 |
| 16 | 2881030 |
| 17 | 5799093 |
| 18 | 11476452 |
| 19 | 22357584 |
| 20 | 42922558 |
| 21 | 81284699 |
| 22 | 151974124 |
| 23 | 280739800 |
| 24 | 512761178 |
| 25 | 926568075 |
| 26 | 1657448779 |
| 27 | 2936506316 |
| 28 | 5155349836 |
| 29 | 8972488674 |
| 30 | 15487146900 |