A087697 - OEIS

A087697

Numbers k such that k + 7 and k - 7 are both prime.

10, 12, 24, 30, 36, 54, 60, 66, 90, 96, 120, 144, 156, 174, 186, 204, 234, 264, 270, 276, 300, 324, 360, 366, 390, 426, 450, 456, 516, 564, 570, 594, 600, 606, 624, 654, 666, 684, 726, 750, 780, 804, 816, 846, 870, 960, 984, 990

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OFFSET

1,1

LINKS

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

MAPLE

select(t -> isprime(t+7) and isprime(t-7), [seq(i, i=8..1000, 2)]); # Robert Israel, Jul 22 2018

MATHEMATICA

Rest[Select[Range[1000], PrimeQ[# - 7] && PrimeQ[# + 7] &]] (* Vincenzo Librandi, Jul 23 2018 *)

PROG

(PARI) isok(n) = isprime(n-7) && isprime(n+7); \\ Michel Marcus, Jul 23 2018

(Magma) [n: n in [5..1000] | IsPrime(n-7) and IsPrime(n+7)]; // Vincenzo Librandi, Jul 23 2018

CROSSREFS

Cf. A014574, A087678, A087679, A087680, A087681, A087682, A087683, A087695, A087696, A088767.

Sequence in context: A022324 A084953 A235686 * A241177 A140972 A108901

Adjacent sequences: A087694 A087695 A087696 * A087698 A087699 A087700

KEYWORD

nonn,easy

AUTHOR

Zak Seidov, Sep 27 2003

STATUS

approved