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

Author

Vladimir Joseph Stephan Orlovsky, Apr 23 2010

Keywords

• nonn

Examples

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

Links

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

Crossrefs

Cf. A097698, A108701, A176681, A176682

Programs

Mathematica

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