%I #10 Aug 22 2021 20:50:40
%S 42,55,91,104,140,153,189,202,238,251,287,294,336,349,385,398,434,447,
%T 483,496,532,545,581,594,630,637,679,692,728,741,777,790,826,839,875,
%U 888,924,937,973,980,1022,1035,1071,1084,1120
%N Numbers k such that 0 and 6 occur juxtaposed in the base-7 representation of k but not of k-1.
%t SequencePosition[Table[If[SequenceCount[IntegerDigits[n,7],{0,6}]>0 || SequenceCount[ IntegerDigits[n,7],{6,0}]>0,1,0],{n,1200}],{0,1}][[All,2]] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Sep 24 2018 *)
%Y Cf. A007093.
%K nonn,base
%O 1,1
%A _Clark Kimberling_
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