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.
Z-_Z^2-_Z^3+_Z^4-x), x=0,20); # _Mark van Hoeij's wiki page.
Z-_Z^2-_Z^3+_Z^4-x), x=0,20); # _Mark van Hoeij has authored 0 sequences.