%I
%S 123,221,255,311,487,561,709,1055,1273,1425,1475,1767,1833,
%T 1893,2127,2391,2475,2595,2769,2895,3053,3183,3543,3627,3765,
%U 3919,4069,4113,4203,4315,4609,4953,5175,5347,5413,5657,6117,6515,6585,6597,6833,6915
%N Values of n such that L(19) and N(19) are both prime, where L(k) = (n^2+n+1)*2^(2*k) + (2*n+1)*2^k + 1, N(k) = (n^2+n+1)*2^k + n.
%C Computed with PARI using commands similar to those used to compute A226921.
%H Vincenzo Librandi and Joerg Arndt, <a href="/A227522/b227522.txt">Table of n, a(n) for n = 1..421</a>
%H Eric L. F. Roettger, <a href="http://people.ucalgary.ca/~hwilliam/files/A_Cubic_Extention_of_the_Lucas_Functions.pdf">A cubic extension of the Lucas functions</a>, Thesis, Dept. of Mathematics and Statistics, Univ. of Calgary, 2009. See page 195.
%Y Cf. A226921A226929, A227448, A227449, A227515A227523.
%K sign,easy
%O 1,1
%A _Vincenzo Librandi_, Jul 14 2013
