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%I #7 Aug 23 2017 16:51:42
%S 40,104,168,232,296,320,360,424,488,552,616,680,744,808,832,872,936,
%T 1000,1064,1128,1192,1256,1320,1344,1384,1448,1512,1576,1640,1704,
%U 1768,1832,1856,1896,1960,2024,2088,2152,2216,2280,2344
%N Numbers n such that string 5,0 occurs in the base 8 representation of n but not of n-1.
%t SequencePosition[Table[If[SequenceCount[IntegerDigits[n,8],{5,0}]>0,1,0],{n,2500}],{0,1}][[All,2]] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Aug 23 2017 *)
%K nonn,base
%O 1,1
%A _Clark Kimberling_