A044294 - OEIS

%I #7 May 09 2018 11:51:55

%S 43,124,205,286,367,387,448,529,610,691,772,853,934,1015,1096,1116,

%T 1177,1258,1339,1420,1501,1582,1663,1744,1825,1845,1906,1987,2068,

%U 2149,2230,2311,2392,2473,2554,2574,2635,2716,2797

%N Numbers n such that string 4,7 occurs in the base 9 representation of n but not of n-1.

%t SequencePosition[Table[If[SequenceCount[IntegerDigits[n,9],{4,7}]>0,1,0],{n,3000}],{0,1}][[All,2]] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, May 09 2018 *)

%K nonn,base

%O 1,1

%A _Clark Kimberling_