%I #9 Aug 17 2023 11:49:31
%S 49,113,177,241,305,369,399,433,497,561,625,689,753,817,881,911,945,
%T 1009,1073,1137,1201,1265,1329,1393,1423,1457,1521,1585,1649,1713,
%U 1777,1841,1905,1935,1969,2033,2097,2161,2225,2289,2353
%N Numbers n such that string 6,1 occurs in the base 8 representation of n but not of n+1.
%t Select[Range[2500],MemberQ[Partition[IntegerDigits[#,8],2,1],{6,1}] && !MemberQ[Partition[ IntegerDigits[#+1,8],2,1],{6,1}]&] (* _Harvey P. Dale_, Jul 28 2012 *)
%t SequencePosition[Table[If[SequenceCount[IntegerDigits[n,8],{6,1}]>0,1,0],{n,2500}],{1,0}][[;;,1]] (* _Harvey P. Dale_, Aug 17 2023 *)
%K nonn,base
%O 1,1
%A _Clark Kimberling_
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