cp's OEIS Frontend

A166936 Positive integers n such that when they are written in binary, the longest palindromic substring (or at least one of which that is tied for longest) in binary n begins and ends with a 0.

%I A166936 #12 Apr 27 2025 11:17:51
%S A166936 2,4,8,10,12,16,20,22,24,26,32,36,38,40,42,44,46,48,52,56,58,64,68,72,
%T A166936 74,76,77,78,80,82,84,88,89,92,94,96,100,104,106,110,112,116,128,136,
%U A166936 137,138,140,142,144,145,148,149,150,152,154,156,157,158,160,162,164
%N A166936 Positive integers n such that when they are written in binary, the longest palindromic substring (or at least one of which that is tied for longest) in binary n begins and ends with a 0.
%H A166936 Harvey P. Dale, <a href="/A166936/b166936.txt">Table of n, a(n) for n = 1..1000</a>
%t A166936 lps0Q[n_]:=Module[{ss=Select[Subsequences[IntegerDigits[n,2]],#==Reverse[#]&],len},len=Max[Length/@ss];AnyTrue[Select[ss,Length[#]==len&],#[[1]]==0&]]; Select[Range[200],lps0Q] (* _Harvey P. Dale_, Apr 27 2025 *)
%Y A166936 Cf. A050430, A166937, A166938.
%K A166936 base,nonn
%O A166936 1,1
%A A166936 _Leroy Quet_, Oct 24 2009
%E A166936 Extended by _Ray Chandler_, Mar 11 2010