A043146 - OEIS

%I #10 May 09 2023 13:14:40

%S 25,31,74,80,123,129,172,175,217,227,270,276,319,325,368,374,417,423,

%T 466,472,515,518,560,570,613,619,662,668,711,717,760,766,809,815,858,

%U 861,903,913,956,962,1005,1011,1054,1060,1103

%N Numbers k such that 3 and 4 occur juxtaposed in the base-7 representation of k but not of k-1.

%t SequencePosition[Table[If[SequenceCount[IntegerDigits[n,7],{3,4}]>0 || SequenceCount[ IntegerDigits[n,7],{4,3}]>0,1,0],{n,1200}],{0,1}][[;;,2]] (* _Harvey P. Dale_, May 09 2023 *)

%Y Cf. A007093.

%K nonn,base

%O 1,1

%A _Clark Kimberling_