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 A103802 Primes p such that 2p - 9 and 2p + 9 are both primes. 4
 7, 11, 19, 31, 59, 61, 79, 101, 151, 179, 229, 311, 359, 389, 409, 521, 709, 719, 751, 809, 971, 1039, 1061, 1151, 1171, 1201, 1361, 1459, 1481, 1669, 1699, 1811, 1949, 1999, 2131, 2341, 2371, 2411, 2609, 2671, 2711, 2791, 2851, 3019, 3041, 3061, 3119 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS FORMULA p, 2p-9 and 2p+9 all are positive and are primes (hence we omit p=2). MATHEMATICA Select[Range[7, 6000], PrimeQ[ # ] && PrimeQ[2# + 9] && PrimeQ[2# - 9] &] okQ[n_]:=Module[{c=2n}, PrimeQ[c+9]&&PrimeQ[c-9]]; Select[Prime[ Range[5, 500]], okQ]  (* Harvey P. Dale, Apr 25 2011 *) PROG (MAGMA) [p: p in PrimesUpTo(3200)| IsPrime(2*p+9) and IsPrime(2*p-9) ]; // Vincenzo Librandi, Jan 28 2011 CROSSREFS Sequence in context: A235806 A238501 A133425 * A038984 A165549 A055939 Adjacent sequences:  A103799 A103800 A103801 * A103803 A103804 A103805 KEYWORD nonn AUTHOR Zak Seidov, Feb 16 2005 STATUS approved

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Last modified December 14 22:42 EST 2019. Contains 329987 sequences. (Running on oeis4.)