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.
(j,j), j=1,2,3,4. - _Simone Severini's wiki page.
(j,j), j=1,2,3,4. - _Simone Severini has authored 0 sequences.