%I #12 Jun 30 2021 03:56:57

%S 45,54,145,154,245,254,345,354,405,415,425,435,450,451,452,453,456,

%T 457,458,459,465,475,485,495,504,514,524,534,540,541,542,543,546,547,

%U 548,549,564,574,584,594,645,654,745,754,845,854,945,954,1045,1054

%N Numbers whose base-10 representation has the same nonzero number of 4's and 5's.

%t Select[Range[1100],DigitCount[#,10,4]==DigitCount[#,10,5]>0&] (* _Harvey P. Dale_, Jul 25 2019 *)

%K nonn,base,easy

%O 1,1

%A _Olivier Gérard_