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.
?(Times @@ Boole@ Map[First@ # > Last@ # &, FactorInteger@ #] > 0 &)] &, Length@ s - 1, 2]] (* _Michael De Vlieger has authored 0 sequences.