A227516 - OEIS

%I #18 Mar 21 2019 04:37:35

%S 25,-33,-285,325,349,-449,-621,661,843,975,-977,991,1035,-1037,-1137,

%T -1191,-1515,-1593,-1625,1683,1693,-1713,1759,-1803,1957,2125,2523,

%U -2531,-2615,2827,-2901,-2999,3033,-3147,3373,3391,3559,3621,3663,-3795,3849,-3855,3891,3957,-3993,-4085,-4317,-4323,-4407,4531,-4617,4633

%N Values of n such that L(13) and N(13) 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, <a href="/A227516/b227516.txt">Table of n, a(n) for n = 1..278</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. A226921-A226929, A227448, A227449, A227515-A227523.

%K sign,easy

%O 1,1

%A _Vincenzo Librandi_, Jul 14 2013