A253142 Numbers n such that n + 15 and n^2 + 15 are prime.

2, 4, 8, 14, 16, 22, 26, 32, 38, 44, 46, 52, 64, 68, 86, 88, 98, 124, 134, 158, 178, 184, 196, 212, 236, 242, 248, 256, 262, 296, 298, 316, 322, 338, 364, 374, 386, 394, 452, 472, 484, 488, 548, 578, 586, 598, 602, 626, 632, 638, 646, 658, 662, 676, 694, 718, 728, 736, 794, 806, 842, 848, 862

Offset

1,1

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Example

2 + 15 = 17 and 2^2 + 15 = 19 are both prime, so 2 is in the sequence.

Maple

select(t -> isprime(t+15) and isprime(t^2+15), [seq(i, i=2..1000, 2)]); # Robert Israel, May 07 2019

Mathematica

p = 15; Select[Range[2, 1000, 2], PrimeQ[p + #^2] && PrimeQ[p + #] &]
Select[Range[2, 1000, 2], AllTrue[{#, #^2}+15, PrimeQ]&] (* Harvey P. Dale, Jun 08 2023 *)

Crossrefs

Intersection of A086303 and A121982.

Sequence in context: A209838 A121982 A143423 * A069049 A124853 A188629

Adjacent sequences: A253139 A253140 A253141 * A253143 A253144 A253145

Keyword

nonn

Author

Zak Seidov, Dec 27 2014

Status

approved