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A087695
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Numbers n such that n + 3 and n - 3 are both prime.
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20
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8, 10, 14, 16, 20, 26, 34, 40, 44, 50, 56, 64, 70, 76, 86, 100, 104, 106, 110, 134, 154, 160, 170, 176, 194, 196, 226, 230, 236, 254, 260, 266, 274, 280, 310, 314, 334, 350, 356, 370, 376, 386, 436, 446, 460, 464, 506, 544, 560, 566, 574, 590, 596
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OFFSET
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1,1
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COMMENTS
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LINKS
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FORMULA
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MAPLE
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ZL:=[]:for p from 1 to 600 do if (isprime(p) and isprime(p+6) ) then ZL:=[op(ZL), (p+(p+6))/2]; fi; od; print(ZL); # Zerinvary Lajos, Mar 07 2007
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MATHEMATICA
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Select[Range[600], AllTrue[#+{3, -3}, PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, May 06 2015 *)
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PROG
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(Haskell)
a087695 n = a087695_list !! (n-1)
a087695_list = filter
(\x -> a010051' (x - 3) == 1 && a010051' (x + 3) == 1) [2, 4 ..]
(PARI) p=2; q=3; forprime(r=5, 1e3, if(q-p<7 && (q-p==6 || r-p==6), print1(p+3", ")); p=q; q=r) \\ Charles R Greathouse IV, May 22 2018
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CROSSREFS
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KEYWORD
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easy,nonn
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AUTHOR
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STATUS
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approved
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