%I #7 Apr 18 2019 11:29:46
%S 50,131,212,293,374,450,536,617,698,779,860,941,1022,1103,1179,1265,
%T 1346,1427,1508,1589,1670,1751,1832,1908,1994,2075,2156,2237,2318,
%U 2399,2480,2561,2637,2723,2804,2885,2966,3047,3128
%N Numbers n such that string 5,5 occurs in the base 9 representation of n but not of n-1.
%t SequencePosition[Table[If[SequenceCount[IntegerDigits[n,9],{5,5}]>0,1,0],{n,3200}],{0,1}][[All,2]] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Apr 18 2019 *)
%K nonn,base
%O 1,1
%A _Clark Kimberling_
|