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 | 0 |
| 2 | 2 |
| 3 | 4 |
| 4 | 20 |
| 5 | 68 |
| 6 | 289 |
| 7 | 1151 |
| 8 | 4792 |
| 9 | 19603 |
| 10 | 80820 |
| 11 | 331373 |