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Numbers whose base-10 representation has the same nonzero number of 3's and 8's.
1

%I #15 Jun 30 2021 03:57:05

%S 38,83,138,183,238,283,308,318,328,348,358,368,378,380,381,382,384,

%T 385,386,387,389,398,438,483,538,583,638,683,738,783,803,813,823,830,

%U 831,832,834,835,836,837,839,843,853,863,873,893,938,983,1038,1083

%N Numbers whose base-10 representation has the same nonzero number of 3's and 8's.

%H Iain Fox, <a href="/A039421/b039421.txt">Table of n, a(n) for n = 1..10000</a>

%t Select[Range[1000], DigitCount[#, 10, 3] == DigitCount[#, 10, 8] > 0 &] (* _Wesley Ivan Hurt_, Nov 21 2017 *)

%o (PARI) is(n) = { my(d = digits(n), i = 0, j = 0); for(x=1, length(d), if(d[x] == 3, i++, if(d[x] == 8, j++))); return(i==j && i!=0); } \\ _Iain Fox_, Nov 21 2017

%K nonn,base,easy

%O 1,1

%A _Olivier GĂ©rard_