%I #10 Aug 23 2021 21:46:47
%S 38,83,138,183,238,283,338,380,438,483,538,583,638,683,738,783,830,
%T 883,938,983,1038,1083,1138,1183,1238,1283,1338,1380,1438,1483,1538,
%U 1583,1638,1683,1738,1783,1830,1883,1938,1983,2038
%N Numbers k such that 3 and 8 occur juxtaposed in the base10 representation of k but not of k1.
%t SequencePosition[Table[If[SequenceCount[IntegerDigits[n],{3,8}]>0  SequenceCount[IntegerDigits[n],{8,3}]>0,1,0],{n,2500}],{0,1}][[All,2]] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Jun 21 2017 *)
%K nonn,base
%O 1,1
%A _Clark Kimberling_
