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%I #27 Apr 23 2023 22:01:04
%S 3,10,17,21,22,23,25,26,27,31,38,45,52,59,66,70,71,72,74,75,76,80,87,
%T 94,101,108,115,119,120,121,123,124,125,129,136,143,147,148,149,151,
%U 152,153,154,155,156,158,159,160,161,162,163,165
%N Numbers whose base-7 representation contains exactly one 3.
%t Select[Range[200], DigitCount[#, 7, 3]==1&] (* _Vincenzo Librandi_, Jul 01 2015 *)
%Y Cf. A007093.
%K nonn,base
%O 1,1
%A _Clark Kimberling_