login
Numbers whose base-9 representation has the same nonzero number of 7's and 8's.
0

%I #14 Jun 30 2021 03:55:16

%S 71,79,152,160,233,241,314,322,395,403,476,484,557,565,575,584,593,

%T 602,611,620,629,639,640,641,642,643,644,645,655,664,673,682,691,700,

%U 709,711,712,713,714,715,716,717,800,808,881,889,962,970,1043,1051

%N Numbers whose base-9 representation has the same nonzero number of 7's and 8's.

%t b9Q[n_]:=Module[{idn9=IntegerDigits[n,9]},Count[idn9,7]==Count[idn9,8]!=0]

%t Select[Range[1100],b9Q] (* _Harvey P. Dale_, Feb 14 2011 *)

%Y Cf. A007095.

%K nonn,base,easy

%O 1,1

%A _Olivier GĂ©rard_