%I A123693
%S A123693 5,491531
%N A123693 Primes p such that p^2 divides 7^(p-1) - 1.
%Y A123693 Cf. A001220, A014127, A123692.
%Y A123693 Sequence in context: A152516 A067502 A067509 this_sequence A111727 A115738 
               A115763
%Y A123693 Adjacent sequences: A123690 A123691 A123692 this_sequence A123694 A123695 
               A123696
%K A123693 bref,hard,nonn
%O A123693 1,1
%A A123693 Max Alekseyev (maxale(AT)gmail.com), Oct 07 2006