%I #8 Jan 18 2019 14:11:09

%S 7,17,70,71,107,117,170,171,257,275,527,572,700,701,710,711,725,752,

%T 1007,1017,1070,1071,1107,1117,1170,1171,1257,1275,1527,1572,1700,

%U 1701,1710,1711,1725,1752,2057,2075,2157,2175

%N Numbers with nonzero multiplicative digital root 7.

%H <a href="/index/Ar#10-automatic">Index entries for 10-automatic sequences</a>.

%F A051802^-1(7)

%t Select[Range[2500],NestWhile[Times@@(IntegerDigits[#]/.(0->1))&,#,#>9&] == 7&] (* _Harvey P. Dale_, Jan 18 2019 *)

%Y Part of histogram of A051802.

%K nonn,easy,base

%O 1,1

%A _Dan Hoey_, Dec 09 1999