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.
4! = Gauss_factorial(2*n,4) = Product's wiki page.
4! = Gauss_factorial(2*n,4) = Product has authored 0 sequences.