A039425 - OEIS

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A039425

Numbers whose base-10 representation has the same nonzero number of 4's and 7's.

%I #10 Jun 30 2021 03:56:51

%S 47,74,147,174,247,274,347,374,407,417,427,437,457,467,470,471,472,

%T 473,475,476,478,479,487,497,547,574,647,674,704,714,724,734,740,741,

%U 742,743,745,746,748,749,754,764,784,794,847,874,947,974,1047,1074

%N Numbers whose base-10 representation has the same nonzero number of 4's and 7's.

%K nonn,base,easy

%O 1,1

%A _Olivier Gérard_