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%I #20 Oct 10 2023 05:13:15
%S 2,5,10,12,19,21,25,38,42,44,50,51,52,56,71,75,76,77,83,85,89,100,101,
%T 102,105,108,113,142,147,150,153,154,155,166,170,172,178,179,180,184,
%U 199,201,202,203,204,205,210,211,212,217,226,227,232,240,271,279,284
%N Numbers having equal length of longest contiguous block of zeros and ones in binary expansion.
%C A087117(a(n)) = A038374(a(n)), see also A000975.
%H Reinhard Zumkeller, <a href="/A090050/b090050.txt">Table of n, a(n) for n = 1..10000</a>
%H <a href="/index/Bi#binary">Index entries for sequences related to binary expansion of n</a>
%e 180 -> '10110100' with A087117(180)=2 and A038374(180)=2, therefore 180 is a term.
%t zobQ[n_]:=Module[{s=Split[IntegerDigits[n,2]]},Max[Length/@Select[ s, MemberQ[ #,0]&]] == Max[Length/@Select[s,MemberQ[#,1]&]]]; Select[ Range[ 300],zobQ] (* _Harvey P. Dale_, Aug 25 2019 *)
%t Select[Range@1000, (s=Split@IntegerDigits[#,2]; Length@s>1 && Last@Differences@(Length@# & /@ Union@s) == 0) &] (* _Hans Rudolf Widmer_, Oct 10 2023 *)
%o (Haskell)
%o a090050 n = a090050_list !! (n+1)
%o a090050_list = [x | x <- [1..], a087117 x == a038374 x]
%o -- _Reinhard Zumkeller_, May 01 2012
%Y Cf. A031443 (binary digitally balanced).
%Y Cf. A000975, A038374, A087117.
%K nonn,base
%O 1,1
%A _Reinhard Zumkeller_, Nov 20 2003
%E Definition corrected, thanks to _Leroy Quet_. - Sep 17 2008
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