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%I #7 Aug 02 2021 10:38:53
%S 15,115,150,215,315,415,515,615,715,815,915,1015,1115,1150,1215,1315,
%T 1415,1500,1615,1715,1815,1915,2015,2115,2150,2215,2315,2415,2515,
%U 2615,2715,2815,2915,3015,3115,3150,3215,3315,3415
%N Numbers n such that string 1,5 occurs in the base 10 representation of n but not of n-1.
%t SequencePosition[Table[If[SequenceCount[IntegerDigits[n],{1,5}]>0,1,0],{n,3500}],{0,1}][[All,2]] (* _Harvey P. Dale_, Aug 02 2021 *)
%K nonn,base
%O 1,1
%A _Clark Kimberling_