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A161866 Numbers n such that n^2+n+7 and n^2+n-7 are both prime. 0
3, 5, 9, 12, 24, 29, 32, 39, 44, 50, 57, 59, 65, 102, 135, 137, 144, 170, 180, 207, 260, 267, 297, 302, 305, 344, 347, 360, 365, 369, 389, 404, 429, 464, 474, 495, 540, 555, 570, 612, 620, 659, 662, 689, 767, 774, 792, 824, 837, 872, 885, 900, 950, 954, 989 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..55.

EXAMPLE

a(1)=3 as 12+-7 are primes. a(2)=5 as 30+-7 are primes.

MATHEMATICA

q=7; lst7={}; Do[p=n^2+n; If[PrimeQ[p-q]&&PrimeQ[p+q], AppendTo[lst7, n]], {n, 0, 7!}]; lst7

CROSSREFS

Cf. A088485, A161863, A161864, A153417.

Sequence in context: A059093 A084593 A275843 * A102968 A180341 A177078

Adjacent sequences:  A161863 A161864 A161865 * A161867 A161868 A161869

KEYWORD

nonn,easy

AUTHOR

Vladimir Joseph Stephan Orlovsky, Jun 20 2009

EXTENSIONS

Definition rephrased by R. J. Mathar, Jun 23 2009

STATUS

approved

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Last modified May 19 13:08 EDT 2019. Contains 323393 sequences. (Running on oeis4.)