A176682 Numbers k such that k^2 +-7 are primes.

6, 12, 18, 36, 48, 60, 66, 132, 138, 162, 186, 192, 216, 228, 270, 330, 360, 366, 408, 468, 474, 582, 606, 642, 678, 708, 744, 792, 1086, 1182, 1236, 1308, 1326, 1458, 1524, 1686, 1782, 1902, 1998, 2040, 2124, 2178, 2208, 2244, 2358, 2370, 2634, 2658, 2760

Offset: 1

Author

Vladimir Joseph Stephan Orlovsky, Apr 23 2010

Keywords

• nonn

Examples

			12 is in the sequence, because 12^2 - 7 = 137 and 12^2 + 7 = 151 are primes.
		

Links

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

Crossrefs

Cf. A097698, A108701, A176681

Programs

Mathematica

Select[Range[8! ],PrimeQ[ #^2-7]&&PrimeQ[ #^2+7]&]