A131530 Numbers k such that k^2 - k - 1 and k^2 - k + 1 are twin primes.

3, 4, 6, 7, 9, 16, 21, 22, 25, 39, 42, 51, 55, 60, 67, 90, 102, 132, 139, 142, 154, 156, 165, 177, 189, 204, 207, 210, 216, 219, 232, 237, 247, 289, 291, 310, 315, 352, 379, 396, 406, 454, 456, 457, 496, 501, 519, 531, 552, 561, 625, 645, 669, 687, 721, 729, 744

Offset

1,1

Links

Seiichi Manyama, Table of n, a(n) for n = 1..5000

Mathematica

Select[Range[744], AllTrue[{#^2-#-1, #^2-#+1}, PrimeQ]&] (* James C. McMahon, Feb 25 2025 *)

Prog

(Magma) [n: n in [0..500] | IsPrime(n^2-n-1) and IsPrime(n^2-n+1)]; // Vincenzo Librandi, Nov 23 2010

Crossrefs

Intersection of A002328 and A055494. - Michel Marcus, Jan 24 2018

Sequence in context: A127594 A094604 A108654 * A285379 A102093 A135215

Adjacent sequences: A131527 A131528 A131529 * A131531 A131532 A131533

Keyword

nonn

Author

Pierre CAMI, Aug 26 2007

Status

approved