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 A190553 #7 Jul 04 2017 18:33:13 %S A190553 2,4,9,14,19,21,26,31,33,38,43,48,50,55,60,62,67,72,74,77,79,84,89,91, %T A190553 96,101,103,108,113,118,120,125,130,132,137,142,144,147,149,154,159, %U A190553 161,166,171,173,178,183,188,190,195,200,202,207,212,217,219,224,229,231,236,241,243,248,253,258,260,265,270,272,277,282,287 %N A190553 Positions of 3 in A190549. %C A190553 See A190549. %H A190553 G. C. Greubel, <a href="/A190553/b190553.txt">Table of n, a(n) for n = 1..1000</a> %t A190553 r = Sqrt[2]; b = 4; c = 1; %t A190553 f[n_] := Floor[(b*n + c)*r] - b*Floor[n*r] - Floor[c*r]; %t A190553 t = Table[f[n], {n, 1, 200}] (* A190549 *) %t A190553 Flatten[Position[t, 0]] (* A190550 *) %t A190553 Flatten[Position[t, 1]] (* A190551 *) %t A190553 Flatten[Position[t, 2]] (* A190552 *) %t A190553 Flatten[Position[t, 3]] (* A190553 *) %t A190553 Flatten[Position[t, 4]] (* A190554 *) %Y A190553 Cf. A190549. %K A190553 nonn %O A190553 1,1 %A A190553 _Clark Kimberling_, May 12 2011