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.
225, which consolidates to 225; erasing all 5's in 225 results in 22's wiki page.
225, which consolidates to 225; erasing all 5's in 225 results in 22 has authored 0 sequences.