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.
n=1; D=g^(n)_n with D_0=1=D_1 and D_n=-2D's wiki page.
n=1; D=g^(n)_n with D_0=1=D_1 and D_n=-2D has authored 0 sequences.