A088255 Duplicate of A075590.
4, 6, 30, 420, 2310, 43890, 1138830, 17160990, 300690390, 17100553470
Offset: 1
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.