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 A305576 #30 Jul 12 2025 16:08:30 %S A305576 0,0,1,0,-1,1,1,-1,-1,0,2,0,-2,1,2,2,1,-1,-2,-2,-1,2,2,-2,-2,0,3,0,-3, %T A305576 1,3,3,1,-1,-3,-3,-1,2,3,3,2,-2,-3,-3,-2,0,4,0,-4,1,4,4,1,-1,-4,-4,-1, %U A305576 3,3,-3,-3,2,4,4,2,-2,-4,-4,-2,0,3,4,5,4,3,0,-3,-4,-5,-4,-3,1 %N A305576 List points (x,y) having integer coordinates, sorted first by radial coordinate r and in case of ties, by polar angle 0 <= phi < 2*Pi in a polar coordinate system. Sequence gives y-coordinates. %C A305576 Similar to A283308, but with secondary sorting by polar angle. %H A305576 Rainer Rosenthal, <a href="/A305576/b305576.txt">Table of n, a(n) for n = 0..17664</a>, covering range r <= 75 (terms 0..7844 from Hugo Pfoertner). %e A305576 See A305575. %o A305576 (PARI) \\ Provided in A305575. %Y A305576 For the x-coordinates see A305575. %Y A305576 Cf. A000328, A004018, A283307, A283308, A307014, A307016, A307017, A308080, A308081. %K A305576 sign,look %O A305576 0,11 %A A305576 _Hugo Pfoertner_, Jun 05 2018