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 A043727 #10 Oct 04 2023 23:44:51 %S A043727 5,9,11,13,17,19,23,25,27,29,33,35,39,47,49,51,55,57,59,61,65,67,71, %T A043727 79,85,95,97,99,103,111,113,115,119,121,123,125,129,131,135,143,149, %U A043727 159,165,169,171,173,181,191,193,195,199,207,213 %N A043727 Numbers whose number of runs in the base-2 representation is congruent to 3 mod 4. %t A043727 Select[Range[300],Mod[Length[Split[IntegerDigits[#,2]]],4]==3&] (* _Harvey P. Dale_, Dec 31 2017 *) %K A043727 nonn,base %O A043727 1,1 %A A043727 _Clark Kimberling_