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%I #24 Jun 27 2021 10:42:14
%S 0,1,2,4,5,6,8,9,10,11,12,13,14,16,17,18,20,21,22,23,24,25,26,28,29,
%T 30,32,33,34,35,43,48,49,50,52,53,54,56,57,58,59,60,61,62,64,65,66,68,
%U 69,70,71,72,73,74,76,77,78,80,81,82,83,87,96,97,98,100,101,102,104
%N Numbers whose base-12 representation has the same number of 3's and 7's.
%t Select[Range[0,120],DigitCount[#,12,3]==DigitCount[#,12,7]&] (* _Harvey P. Dale_, May 04 2011 *)
%o (PARI) isok(n) = my(d=digits(n, 12)); #select(x->(x==3), d) == #select(x->(x==7), d); \\ _Michel Marcus_, Feb 05 2019
%Y Cf. A039138 (same in base 10).
%K nonn,base,easy
%O 1,3
%A _Olivier Gérard_