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) |
|---|---|
| 3 | 1 |
| 4 | 12 |
| 5 | 54 |
| 6 | 188 |
| 7 | 636 |
| 8 | 2168 |
| 9 | 7556 |
| 10 | 26826 |
| 11 | 96724 |
| 12 | 353390 |
| 13 | 1305126 |
| 14 | 4864450 |
| 15 | 18272804 |
| 16 | 69103526 |
| 17 | 262871644 |
| 18 | 1005137688 |
| 19 | 3860909698 |
| 20 | 14890903690 |
| 21 | 57641869140 |
| 22 | 223864731680 |
| 23 | 872028568182 |
| 24 | 3406103773674 |
| 25 | 13337263822236 |