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 A131853 #15 Oct 12 2021 08:01:22
%S A131853 0,5,10,15,20,30,40,45,60,65,75,80,85,90,95,105,120,125,130,135,150,
%T A131853 160,165,170,175,180,190,195,210,215,225,235,240,245,250,255,260,270,
%U A131853 300,320,325,330,335,340,350,360,365,380,390,420,430,450,455,470,480,485
%N A131853 Numbers m such that z(m)=(0,0) with z as defined in A131851.
%C A131853 Intersection of A131854 and A131855: A131851(a(n))=0, A131852(a(n))=0;
%C A131853 conjecture: a(n) mod 5 = 0.
%H A131853 Seiichi Manyama, <a href="/A131853/b131853.txt">Table of n, a(n) for n = 1..10000</a> (terms 1..1000 from Reinhard Zumkeller)
%t A131853 z[n_] := z[n] = If[n == 0, 0, z[Floor[n/2]] I + Mod[n, 2]];
%t A131853 Flatten[Position[Table[z[n], {n, 0, 500}], 0] - 1] (* _Jean-François Alcover_, Oct 12 2021 *)
%Y A131853 Cf. A131851, A131856, A131858, A131860, A008587.
%K A131853 nonn
%O A131853 1,2
%A A131853 _Reinhard Zumkeller_, Jul 22 2007