%I #7 Mar 24 2016 11:38:59
%S 12,28,44,51,60,76,92,108,115,124,140,156,172,179,188,207,220,236,243,
%T 252,268,284,300,307,316,332,348,364,371,380,396,412,428,435,444,463,
%U 476,492,499,508,524,540,556,563,572,588,604
%N Numbers n such that string 3,0 occurs in the base 4 representation of n but not of n+1.
%t Transpose[SequencePosition[Table[If[SequenceCount[IntegerDigits[n,4],{3,0}]>0,1,0],{n,700}],{1,0}]][[1]] (* The program uses the SequencePosition and SequenceCount functions from Mathematica version 10 *) (* _Harvey P. Dale_, Mar 24 2016 *)
%K nonn,base
%O 1,1
%A _Clark Kimberling_