This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A043167 #15 Jun 02 2024 13:36:43
%S A043167 21,42,85,106,149,168,213,234,277,298,336,362,405,426,469,490,533,554,
%T A043167 597,618,661,680,725,746,789,810,848,874,917,938,981,1002,1045,1066,
%U A043167 1109,1130,1173,1192,1237,1258,1301,1322,1344
%N A043167 Numbers k such that 2 and 5 occur juxtaposed in the base-8 representation of k but not of k-1.
%H A043167 Harvey P. Dale, <a href="/A043167/b043167.txt">Table of n, a(n) for n = 1..1000</a>
%t A043167 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 A043167 Cf. A007094.
%K A043167 nonn,base
%O A043167 1,1
%A A043167 _Clark Kimberling_