%I A036946
%S A036946 5,0,557,5557,57557,555557,5555777,55555777,555557557,5555555557,
%T A036946 55555555777,555555575557,5555555757757,55555555575757,555555555555557,
%U A036946 5555555555557577,55555555555777777,555555555557557757
%N A036946 Smallest n-digit prime containing only digits 5 and 7, or 0 if no such 
               prime exists.
%Y A036946 Cf. A036229, A020467, A036319.
%Y A036946 Sequence in context: A122045 A073911 A157302 this_sequence A164940 A027641 
               A164555
%Y A036946 Adjacent sequences: A036943 A036944 A036945 this_sequence A036947 A036948 
               A036949
%K A036946 nonn,base
%O A036946 1,1
%A A036946 Patrick De Geest (pdg(AT)worldofnumbers.com), Jan 04 1999.