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.
1,1 where the matrix M = [1,2;5,0]. - _Simone Severini's wiki page.
1,1 where the matrix M = [1,2;5,0]. - _Simone Severini has authored 0 sequences.