%I #7 Oct 11 2017 19:21:01
%S 19,35,51,67,79,83,99,115,131,143,147,163,179,195,207,211,227,243,259,
%T 271,275,291,319,323,335,339,355,371,387,399,403,419,435,451,463,467,
%U 483,499,515,527,531,547,575,579,591,595,611
%N Numbers n such that string 0,3 occurs in the base 4 representation of n but not of n+1.
%t SequencePosition[Table[If[SequenceCount[IntegerDigits[n,4],{0,3}]>0,1,0],{n,700}],{1,0}][[All,1]] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Oct 11 2017 *)
%K nonn,base
%O 1,1
%A _Clark Kimberling_