A052398 Duplicate of A047890.
1, 2, 6, 24, 120, 719, 5003, 39429, 344837, 3291590, 33835114, 370531683
Offset: 0
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.