%I #7 Feb 19 2020 15:16:22
%S 14,114,149,214,314,414,514,614,714,814,914,1014,1114,1149,1214,1314,
%T 1499,1514,1614,1714,1814,1914,2014,2114,2149,2214,2314,2414,2514,
%U 2614,2714,2814,2914,3014,3114,3149,3214,3314,3414
%N Numbers n such that string 1,4 occurs in the base 10 representation of n but not of n+1.
%t SequencePosition[Table[If[SequenceCount[IntegerDigits[n],{1,4}]>0,1,0],{n,3500}],{1,0}][[All,1]] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Feb 19 2020 *)
%K nonn,base
%O 1,1
%A _Clark Kimberling_