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) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 2 |
| 5 | 4 |
| 6 | 11 |
| 7 | 28 |
| 8 | 78 |
| 9 | 212 |
| 10 | 598 |
| 11 | 1686 |
| 12 | 4841 |
| 13 | 13975 |
| 14 | 40777 |
| 15 | 119698 |
| 16 | 353905 |
| 17 | 1051948 |
| 18 | 3143582 |
| 19 | 9436033 |
| 20 | 28443340 |
| 21 | 86055366 |
| 22 | 261253380 |
| 23 | 795587214 |
| 24 | 2429692385 |
| 25 | 7439569568 |
| 26 | 22834518491 |
| 27 | 70243063795 |
| 28 | 216527666056 |