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Semiprimes in carryless digital root arithmetic in base 10.
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%I #5 May 01 2013 21:10:57

%S 9,30,33,36,39,60,63,66,69,93,96,100,110,113,116,117,119,120,121,123,

%T 126,129,130,132,135,138,139,140,143,144,146,149,150,153,154,156,159,

%U 160,162,165,168,169,170,171,173,176,179,180,183,186,187,189,190,192,195,198,199

%N Semiprimes in carryless digital root arithmetic in base 10.

%C Products of pairs of elements of A169911 in carryless digital root arithmetic in base 10.

%H <a href="/index/Ca#CARRYLESS">Index entries for sequences related to carryless arithmetic</a>

%e a(1) = 9 because the smallest prime in carryless digital root arithmetic in base 10 is 3, and 3*3 = 9.

%Y Cf. A169911.

%K base,nonn

%O 1,1

%A _Jonathan Vos Post_, Jul 17 2010

%E Edited and corrected by _N. J. A. Sloane_, Jul 17 2010