A227521 Values of n such that L(18) and N(18) 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.

-101, 625, -665, -1151, -1211, 1411, 2209, -2945, 3469, -4391, 4681, -4895, -5945, -6281, -6305, 6529, 8125, -8249, 8269, -8321, 8605, 9025, -9821, -10439, 11659, 13729, -14429, 14821, 14875, 15031, -15545, -15575, 15601, -15815, 17215, -17435, -17615, 17899, -18965, 19555, -19775

Offset

1,1

Comments

Computed with PARI using commands similar to those used to compute A226921.

Links

Vincenzo Librandi and Joerg Arndt, Table of n, a(n) for n = 1..338

Eric L. F. Roettger, A cubic extension of the Lucas functions, Thesis, Dept. of Mathematics and Statistics, Univ. of Calgary, 2009. See page 195.

Crossrefs

Cf. A226921-A226929, A227448, A227449, A227515-A227523.

Sequence in context: A142507 A131697 A153806 * A364147 A171813 A089291

Adjacent sequences: A227518 A227519 A227520 * A227522 A227523 A227524

Keyword

sign,easy

Author

Vincenzo Librandi, Jul 14 2013

Status

approved