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.
?(Nor[CoprimeQ[#, n], PowerMod[n, Floor@ Log2@ n, #] == 0] &)], {n, 312}]] (* _Michael De Vlieger has authored 0 sequences.