A122062 Numbers k such that k^2 + 16 is prime.

1, 5, 9, 11, 15, 21, 25, 29, 31, 41, 49, 51, 55, 65, 75, 79, 81, 89, 91, 95, 99, 109, 115, 119, 121, 125, 129, 151, 165, 179, 191, 211, 219, 221, 229, 231, 245, 249, 265, 275, 281, 289, 291, 295, 299, 301, 311, 315, 335, 351, 355, 361, 365, 369, 381, 389, 391

Offset: 1

Author

Parthasarathy Nambi, Sep 14 2006

Keywords

• nonn

Examples

			If k=99 then k^2 + 16 = 9817 (prime).
		

Links

• Daniel Starodubtsev, Table of n, a(n) for n = 1..5000

Crossrefs

Cf. A005574, A067201, A049422, A007591, A078402, A114269, A114271, A114272, A114273, A114274, A114275, A113536, A121250, A121982.

Programs

Magma

[n: n in [0..6000] | IsPrime(n^2 + 16)]; // Vincenzo Librandi, Nov 13 2010

Mathematica

Select[Range[1,501,2],PrimeQ[16+#^2]&] (* Harvey P. Dale, Dec 04 2018 *)

PARI

is(n)=isprime(n^2+16) \\ Charles R Greathouse IV, Jun 06 2017