A113536 Numbers k such that k^2 + 13 is prime.

0, 2, 4, 10, 12, 16, 18, 28, 40, 42, 44, 46, 60, 68, 72, 82, 84, 88, 94, 108, 110, 114, 116, 122, 126, 142, 144, 152, 158, 180, 192, 194, 198, 200, 220, 222, 264, 266, 268, 282, 284, 296, 298, 332, 336, 340, 354, 378, 380, 418, 420, 430, 434, 446, 464, 466, 486

Offset: 1

Author

Zak Seidov, Jan 13 2006

Keywords

• nonn

Examples

			If n=40 then n^2 + 13 = 1613 (prime), so 40 is in the sequence.
		

Links

• G. C. Greubel, Table of n, a(n) for n = 1..1000

Crossrefs

Other cases: A005574 k=1, A067201 k=2, A049422 k=3, A007591 k=4, A078402 k=5, A114269-A114275 k=6-12.

Programs

Mathematica

With[{k=13}, Select[Range[1000], PrimeQ[ #^2+k]&]]

PARI

is(n)=isprime(n^2+13) \\ Charles R Greathouse IV, Feb 17 2017

Extensions

Edited by R. J. Mathar, Aug 07 2008