A176683 Numbers k such that k^2 +-11 are primes.

90, 120, 210, 270, 300, 510, 690, 720, 780, 960, 1200, 2190, 4260, 4350, 4470, 4920, 4980, 5040, 5100, 5250, 5550, 5670, 5730, 5790, 6810, 8100, 8280, 8490, 8610, 9150, 9540, 9990, 10140, 10200, 10650, 11130, 11430, 12060, 12510, 12930, 13770, 13800

Offset

1,1

Links

Daniel Starodubtsev, Table of n, a(n) for n = 1..10000

Example

90 is in the sequence, because 90^2 - 11 = 8089 and 90^2 + 11 = 8111 are primes.

Mathematica

Select[Range[8! ], PrimeQ[ #^2-11]&&PrimeQ[ #^2+11]&]
Select[Range[14000], AllTrue[#^2+{11, -11}, PrimeQ]&] (* Harvey P. Dale, Aug 03 2024 *)

Crossrefs

Cf. A097698, A108701, A176681, A176682

Sequence in context: A039401 A044004 A078493 * A135197 A025371 A025362

Adjacent sequences: A176680 A176681 A176682 * A176684 A176685 A176686

Keyword

nonn

Author

Vladimir Joseph Stephan Orlovsky, Apr 23 2010

Status

approved