%I #10 Aug 23 2021 20:52:31
%S 36,63,136,163,236,263,336,360,436,463,536,563,630,663,736,763,836,
%T 863,936,963,1036,1063,1136,1163,1236,1263,1336,1360,1436,1463,1536,
%U 1563,1630,1663,1736,1763,1836,1863,1936,1963,2036
%N Numbers k such that 3 and 6 occur juxtaposed in the base10 representation of k but not of k1.
%t SequencePosition[Table[If[SequenceCount[IntegerDigits[n],{3,6}]>0  SequenceCount[ IntegerDigits[n],{6,3}]>0,1,0],{n,2100}],{0,1}][[All,2]] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Sep 18 2019 *)
%K nonn,base
%O 1,1
%A _Clark Kimberling_
