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Numbers with exactly four distinct base-7 digits.
0

%I #14 Aug 10 2021 14:14:32

%S 360,361,362,363,366,368,369,370,373,374,376,377,380,381,382,384,387,

%T 388,389,390,444,445,446,447,462,466,467,468,469,472,474,475,476,479,

%U 480,482,483,486,487,488,492,494,495,496,504

%N Numbers with exactly four distinct base-7 digits.

%t db74Q[n_]:=Count[DigitCount[n,7],_?(#>0&)]==4; Select[Range[600],db74Q] (* _Harvey P. Dale_, Oct 21 2017 *)

%Y Cf. A007093.

%K nonn,base

%O 1,1

%A _Clark Kimberling_