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 | 0 |
| 3 | 1 |
| 4 | 1 |
| 5 | 5 |
| 6 | 9 |
| 7 | 33 |
| 8 | 85 |
| 9 | 276 |
| 10 | 827 |
| 11 | 2693 |
| 12 | 8626 |
| 13 | 28639 |
| 14 | 95393 |
| 15 | 323367 |
| 16 | 1104525 |
| 17 | 3813797 |
| 18 | 13266366 |
| 19 | 46509357 |
| 20 | 164098390 |