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Semiprimes with non-semiprimes digits (no digits 4,6,9 in semiprimes).
1

%I #5 Mar 30 2012 18:40:28

%S 10,15,21,22,25,33,35,38,51,55,57,58,77,82,85,87,111,115,118,121,122,

%T 123,133,155,158,177,178,183,185,187,201,202,203,205,213,215,217,218,

%U 221,235,237,253,278,287,301,302,303,305,321,323,327,335,355,358,371

%N Semiprimes with non-semiprimes digits (no digits 4,6,9 in semiprimes).

%C Complement of A107342 in the class of semiprimes.

%C This is to semiprimes A001358 as A034844 (Primes with nonprime digits) is to primes A000040. [_Jonathan Vos Post_, Jul 15 2010]

%F {j in A001358 and j not in A179463}. [_Jonathan Vos Post_, Jul 15 2010]

%t cnd[n_]:=Plus@@Last/@FactorInteger[n]==2&&Union[FreeQ[IntegerDigits[n], # ]&/@{4, 6, 9}]=={True};Select[Range[600], cnd[ # ]&]

%Y Cf. A107342, A137167.

%Y Cf. A107665, A107666, A111494, A111496, A111697, A179336. [_Jonathan Vos Post_, Jul 15 2010]

%K nonn,base

%O 1,1

%A _Zak Seidov_, Jun 13 2005