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.
, Prime[a[n-1]]]; Table[a[n], {n, 1, 16}] (* _Jean-François Alcover's wiki page.
, Prime[a[n-1]]]; Table[a[n], {n, 1, 16}] (* _Jean-François Alcover has authored 0 sequences.