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A179038 Emirps whose only prime digits are 7's. 1

%I

%S 17,71,79,97,107,167,179,701,709,761,769,907,967,971,1097,1471,1487,

%T 1741,1789,1847,1867,1879,1979,7177,7187,7481,7649,7681,7687,7699,

%U 7717,7817,7841,7867,7879,7901,7949,9467,9479,9497,9679,9749,9769,9781,9787

%N Emirps whose only prime digits are 7's.

%t okQ[n_]:=Module[{idn=IntegerDigits[n],rev},rev=Reverse[idn];idn!=rev && Union[Select[idn,PrimeQ]]=={7}&&PrimeQ[FromDigits[rev]]]; Select[ Prime[ Range[1300]],okQ] (* _Harvey P. Dale_, Jul 18 2011 *)

%Y Cf. A006567, A179039.

%K base,nonn

%O 1,1

%A _Lekraj Beedassy_, Jun 25 2010

%E Terms confirmed by _Ray Chandler_, Jul 13 2010

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Last modified February 2 18:58 EST 2023. Contains 360023 sequences. (Running on oeis4.)