A216572 - cp's OEIS frontend

A216572 Numbers n such that the n-th Lucas number is prime, but cannot be written in the form a^2 + 6*b^2.

%I A216572 #12 May 02 2013 13:09:55
%S A216572 0,2,5,7,8,13,16,17,19,31,37,41,47,53,61,71,79,113,353,503,613,617,
%T A216572 863,1097,1361,4793,5851,7741,8467,13963,19469,81671,89849,94823,
%U A216572 140057,159521,183089,344293,443609,532277,574219,631181,637751,651821
%N A216572 Numbers n such that the n-th Lucas number is prime, but cannot be written in the form a^2 + 6*b^2.
%H A216572 Blair Kelly, <a href="http://mersennus.net/fibonacci">Factorizations of Fibonacci and Lucas numbers</a>
%Y A216572 Cf. A000032, A001606.
%K A216572 nonn
%O A216572 1,2
%A A216572 _V. Raman_, Sep 08 2012

cp's OEIS Frontend

A216572 Numbers n such that the n-th Lucas number is prime, but cannot be written in the form a^2 + 6*b^2.