%I #11 Aug 26 2021 03:17:11

%S 20,34,84,98,148,167,212,226,279,290,340,354,404,418,468,482,532,546,

%T 596,610,660,679,724,738,791,802,852,866,916,930,980,994,1044,1058,

%U 1108,1122,1172,1191,1236,1250,1343,1364,1378,1428

%N Numbers k such that 2 and 4 occur juxtaposed in the base-8 representation of k but not of k+1.

%t SequencePosition[Table[If[SequenceCount[IntegerDigits[n,8],{2,4}]>0 || SequenceCount[IntegerDigits[n,8],{4,2}]>0,1,0],{n,1500}],{1,0}][[All,1]] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Jul 25 2020 *)

%Y Cf. A007094.

%K nonn,base

%O 1,1

%A _Clark Kimberling_