A227518 Values of n such that L(15) and N(15) 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.

9, 25, 39, -105, 105, -107, 235, 313, 397, 415, -471, 639, -773, -885, 919, 957, -1053, -1115, -1151, 1279, -1325, 1327, -1377, 1563, -1641, -1703, -1811, -1851, 2007, 2023, -2441, -2501, 2553, -2621, -2681, 2685, -2691, 2937, -2943, -3047, -3491, 3493, 3603, -3677, 3733, -3965, 4083, 4317, -4623, -4737, -4805, -5043, -5063, -5481, -5757, 5805, 5947

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..1000

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: A241764 A044451 A114057 * A031036 A371086 A348749

Adjacent sequences: A227515 A227516 A227517 * A227519 A227520 A227521

Keyword

sign,easy

Author

Vincenzo Librandi, Jul 14 2013

Status

approved