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%I #11 Aug 27 2021 01:45:00
%S 41,49,122,130,203,211,284,292,365,377,449,454,527,535,608,616,689,
%T 697,770,778,851,859,932,940,1013,1021,1094,1106,1178,1183,1256,1264,
%U 1337,1345,1418,1426,1499,1507,1580,1588,1661,1669
%N Numbers k such that 4 and 5 occur juxtaposed in the base-9 representation of k but not of k+1.
%t Transpose[SequencePosition[Table[If[SequenceCount[IntegerDigits[n,9],{4,5}]+SequenceCount[IntegerDigits[n,9],{5,4}]>0,1,0],{n,1700}],{1,0}]][[1]] (* The program uses the SequencePosition and SequenceCount functions from Mathematica version 10 *) (* _Harvey P. Dale_, Oct 03 2015 *)
%Y Cf. A007095.
%K nonn,base
%O 1,1
%A _Clark Kimberling_
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