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 A190701 #7 Jul 04 2017 18:34:22 %S A190701 2,6,10,13,17,21,28,32,36,39,43,47,51,54,58,62,69,73,77,80,84,88,92, %T A190701 95,99,103,107,110,114,118,125,129,133,136,140,144,148,151,155,159, %U A190701 163,166,170,174,181,185,189,192,196,200,204,207,211,215,219,222,226,230,237,241,245,248,252,256,260,263,267,271,278,282,286,289,293 %N A190701 Positions of 2 in A190698. %C A190701 See A190698. %H A190701 G. C. Greubel, <a href="/A190701/b190701.txt">Table of n, a(n) for n = 1..1000</a> %t A190701 r = Sqrt[3]; b = 4; c = 1; %t A190701 f[n_] := Floor[(b*n + c)*r] - b*Floor[n*r] - Floor[c*r]; %t A190701 t = Table[f[n], {n, 1, 200}] (* A190698 *) %t A190701 Flatten[Position[t, 0]] (* A190699 *) %t A190701 Flatten[Position[t, 1]] (* A190700 *) %t A190701 Flatten[Position[t, 2]] (* A190701 *) %t A190701 Flatten[Position[t, 3]] (* A190702 *) %t A190701 Flatten[Position[t, 4]] (* A190703 *) %Y A190701 Cf. A190698. %K A190701 nonn %O A190701 1,1 %A A190701 _Clark Kimberling_, May 17 2011