A101613 (2n)! * Sum[k=n..2n, 1/k].
3, 26, 684, 35664, 3068640, 392722560, 69878833920, 16484477184000, 4976250951168000, 1870345490614272000, 856314330237628416000, 469109144339151224832000, 302956190548293037916160000
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.