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 A043726 #10 Oct 04 2023 23:44:55 %S A043726 2,4,6,8,12,14,16,24,28,30,32,42,48,56,60,62,64,74,82,84,86,90,96,106, %T A043726 112,120,124,126,128,138,146,148,150,154,162,164,166,168,172,174,178, %U A043726 180,182,186,192,202,210,212,214,218,224,234,240 %N A043726 Numbers whose number of runs in the base-2 representation is congruent to 2 mod 4. %C A043726 All terms are even. - _Harvey P. Dale_, Sep 26 2018 %t A043726 Select[Range[2,250,2],Mod[Length[Split[IntegerDigits[#,2]]],4]==2&] (* _Harvey P. Dale_, Sep 26 2018 *) %K A043726 nonn,base %O A043726 1,1 %A A043726 _Clark Kimberling_