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 A043571 #17 Mar 09 2025 16:00:08 %S A043571 10,18,20,22,26,34,36,38,40,44,46,50,52,54,58,66,68,70,72,76,78,80,88, %T A043571 92,94,98,100,102,104,108,110,114,116,118,122,130,132,134,136,140,142, %U A043571 144,152,156,158,160,176,184,188,190,194,196 %N A043571 Numbers whose base-2 representation has exactly 4 runs. %C A043571 There are no odd terms. - _Harvey P. Dale_, Mar 09 2025 %H A043571 Harvey P. Dale, <a href="/A043571/b043571.txt">Table of n, a(n) for n = 1..1000</a> %t A043571 Select[Range[2,200,2],Length[Split[IntegerDigits[#,2]]]==4&] (* _Harvey P. Dale_, Mar 09 2025 *) %K A043571 nonn,base %O A043571 1,1 %A A043571 _Clark Kimberling_