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Numbers with nonzero multiplicative digital root 2.
2

%I #8 Feb 13 2017 21:06:13

%S 2,12,20,21,26,34,37,43,45,54,59,62,69,73,95,96,102,112,120,121,126,

%T 134,137,143,145,154,159,162,169,173,195,196,200,201,206,210,211,216,

%U 223,225,232,239,252,260,261,268,278,279,286

%N Numbers with nonzero multiplicative digital root 2.

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

%F A051802^-1(2)

%t nzd[n_]:=Select[IntegerDigits[n],#!=0&]; dr2Q[m_]:=NestWhile[Times@@ nzd[#]&, m,#>9&]==2; Select[Range[300],dr2Q] (* _Harvey P. Dale_, Jul 01 2015 *)

%Y Part of histogram of A051802.

%K nonn,easy,base

%O 1,1

%A _Dan Hoey_, Dec 09 1999