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Numbers n such that the n-th Lucas number is prime and can be written in the form a^2 + 5*b^2.
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%I #12 May 02 2013 13:10:42

%S 4,13,31,61,313,613,5851,7741,13963,193201,344293,387433

%N Numbers n such that the n-th Lucas number is prime and can be written in the form a^2 + 5*b^2.

%H Blair Kelly, <a href="http://mersennus.net/fibonacci">Factorizations of Fibonacci and Lucas numbers</a>

%Y Cf. A000032, A001606.

%K nonn

%O 1,1

%A _V. Raman_, Sep 08 2012