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.
%I A165924 #6 Aug 10 2015 00:26:38 %S A165924 0,0,0,0,1,1,1,1,1,2,2,2,3,3,2,2,4,3,3,3,4,5,6,4,4,5,4,5,7,5,8,4,6,7, %T A165924 4,5,8,8,7,7,10,7,7,7,6,11,12,5,9,8,7,9,11,10,9,10,10,12,12,9,14,15,8, %U A165924 6,9,12,12,11,14,11,20,10,17,14,9,13,10,13,18,8,12,17,17,11,12,17 %N A165924 a(n) = number of squareful nonzero quadratic residues of n. %H A165924 C. H. Gribble, <a href="/A165924/b165924.txt">Table of n, a(n) for n=1..1000</a>. %Y A165924 Cf. A165919. %K A165924 nonn %O A165924 1,10 %A A165924 _Christopher Hunt Gribble_, Sep 30 2009