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 A043724 #15 Oct 04 2023 10:46:33 %S A043724 10,18,20,22,26,34,36,38,40,44,46,50,52,54,58,66,68,70,72,76,78,80,88, %T A043724 92,94,98,100,102,104,108,110,114,116,118,122,130,132,134,136,140,142, %U A043724 144,152,156,158,160,170,176,184,188,190,194,196,198,200,204,206 %N A043724 Numbers whose number of runs in the base-2 representation is congruent to 0 mod 4. %H A043724 Harvey P. Dale, <a href="/A043724/b043724.txt">Table of n, a(n) for n = 1..1000</a> %t A043724 Select[Range[200],Divisible[Length[Split[IntegerDigits[#,2]]],4]&] (* _Harvey P. Dale_, May 21 2012 *) %o A043724 (PARI) isok(k) = (hammingweight(bitxor(k, k>>1)) % 4) == 0; \\ _Michel Marcus_, Oct 04 2023 %Y A043724 Cf. A005811. %K A043724 nonn,base %O A043724 1,1 %A A043724 _Clark Kimberling_