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 | 12 |
| 3 | 90 |
| 4 | 522 |
| 5 | 2595 |
| 6 | 11673 |
| 7 | 49014 |
| 8 | 195828 |
| 9 | 753813 |
| 10 | 2819475 |
| 11 | 10308144 |
| 12 | 36998118 |
| 13 | 130786695 |
| 14 | 456452493 |
| 15 | 1575799290 |
| 16 | 5389290792 |
| 17 | 18281487081 |
| 18 | 61569776727 |
| 19 | 206040460212 |
| 20 | 685584843450 |
| 21 | 2269566343611 |
| 22 | 7478425876977 |
| 23 | 24538396875870 |
| 24 | 80206515476892 |
| 25 | 261239771497725 |