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A023231
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Primes p such that 8*p + 7 is also prime.
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6
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2, 3, 5, 23, 29, 47, 53, 59, 89, 107, 113, 137, 179, 197, 227, 233, 257, 263, 293, 317, 359, 389, 419, 509, 557, 587, 593, 599, 617, 653, 659, 683, 839, 857, 863, 887, 947, 977, 1013, 1097, 1103, 1163, 1193, 1217, 1223, 1229, 1259, 1277, 1283, 1307, 1319, 1409
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OFFSET
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1,1
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LINKS
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EXAMPLE
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For p = 3, 8*p + 7 = 31;
for p = 179, 8*p + 7 = 1439.
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MAPLE
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a := proc (n) if isprime(n) = true and isprime(8*n+7) = true then n else end if end proc: seq(a(n), n = 1 .. 1500); # Emeric Deutsch, Dec 30 2008
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MATHEMATICA
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PROG
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(Magma) [n: n in PrimesUpTo(1500) | IsPrime(8*n+7)]; // Vincenzo Librandi, Nov 20 2010
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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