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%I #11 Aug 23 2021 01:07:13
%S 16,64,97,144,178,226,259,307,340,388,421,469,502,550,576,631,664,712,
%T 745,793,826,873,907,955,988,1036,1069,1117,1150,1198,1231,1279,1296,
%U 1393,1441,1474,1522,1555,1602,1636,1684,1717
%N Numbers k such that 1 and 7 occur juxtaposed in the base-9 representation of k but not of k-1.
%t SequencePosition[Table[If[SequenceCount[IntegerDigits[n,9],{1,7}]>0 || SequenceCount[ IntegerDigits[n,9],{7,1}]>0,1,0],{n,1800}],{0,1}][[All,2]] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Aug 03 2018 *)
%Y Cf. A007095.
%K nonn,base
%O 1,1
%A _Clark Kimberling_
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