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 A190438 #9 Apr 05 2018 05:54:09
%S A190438 4,7,9,12,15,17,20,25,28,30,33,38,41,43,46,49,51,54,59,62,64,67,70,72,
%T A190438 75,80,83,85,88,93,96,98,101,104,106,109,114,117,119,122,127,130,132,
%U A190438 135,138,140,143,148,151,153,156,159,161,164,169,172,174,177,182,185,187,190,193,195,198,203,206,208,211,214,216,219
%N A190438 Positions of 1 in A190436.
%C A190438 See A190436.
%H A190438 G. C. Greubel, <a href="/A190438/b190438.txt">Table of n, a(n) for n = 1..10000</a>
%t A190438 r = GoldenRatio; b = 3; c = 2;
%t A190438 f[n_] := Floor[(b*n + c)*r] - b*Floor[n*r] - Floor[c*r];
%t A190438 t = Table[f[n], {n, 1, 320}] (* A190436 *)
%t A190438 Flatten[Position[t, 0]] (* A190437 *)
%t A190438 Flatten[Position[t, 1]] (* A190438 *)
%t A190438 Flatten[Position[t, 2]] (* A190439 *)
%t A190438 Flatten[Position[t, 3]] (* A302253 *)
%Y A190438 Cf. A190436.
%K A190438 nonn
%O A190438 1,1
%A A190438 _Clark Kimberling_, May 10 2011