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Numbers n such that the n-th Lucas number is prime, but cannot be written in the form a^2 + 6*b^2.
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%I #12 May 02 2013 13:09:55

%S 0,2,5,7,8,13,16,17,19,31,37,41,47,53,61,71,79,113,353,503,613,617,

%T 863,1097,1361,4793,5851,7741,8467,13963,19469,81671,89849,94823,

%U 140057,159521,183089,344293,443609,532277,574219,631181,637751,651821

%N Numbers n such that the n-th Lucas number is prime, but cannot be written in the form a^2 + 6*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 1,2

%A _V. Raman_, Sep 08 2012