A043167 - OEIS

%I #15 Jun 02 2024 13:36:43

%S 21,42,85,106,149,168,213,234,277,298,336,362,405,426,469,490,533,554,

%T 597,618,661,680,725,746,789,810,848,874,917,938,981,1002,1045,1066,

%U 1109,1130,1173,1192,1237,1258,1301,1322,1344

%N Numbers k such that 2 and 5 occur juxtaposed in the base-8 representation of k but not of k-1.

%H Harvey P. Dale, <a href="/A043167/b043167.txt">Table of n, a(n) for n = 1..1000</a>

%t SequencePosition[Table[If[SequenceCount[IntegerDigits[n,8],{2,5}]>0 || SequenceCount[ IntegerDigits[ n,8],{5,2}]>0,1,0],{n,1500}],{0,1}][[;;,2]] (* _Harvey P. Dale_, Jun 02 2024 *)

%Y Cf. A007094.

%K nonn,base

%O 1,1

%A _Clark Kimberling_