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A199427
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Numbers n such that 4n+1 and 8n+3 are prime.
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1
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1, 7, 10, 13, 22, 28, 43, 58, 70, 73, 127, 148, 160, 163, 190, 202, 238, 253, 262, 307, 322, 352, 370, 400, 433, 472, 475, 493, 517, 532, 535, 568, 598, 637, 673, 685, 688, 742, 832, 847, 853, 862, 898, 940, 955, 1018, 1087, 1093, 1102, 1120, 1183, 1198, 1270
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OFFSET
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1,2
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COMMENTS
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According to Beiler: the integer 2 is a primitive root of all primes of the form 8n+3 provided 4n+1 is a prime.
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REFERENCES
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Albert H. Beiler: Recreations in the theory of numbers. New York: Dover, (2nd ed.) 1966, p. 102, nr. 4.
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LINKS
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Vincenzo Librandi, Table of n, a(n) for n = 1..10000
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FORMULA
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a(n) = intersection(A005098, A005124).
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EXAMPLE
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For n = 1, both 11 and 5 are primes, hence 2 is a primitive root of 11.
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MATHEMATICA
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Select[Range[1270], PrimeQ[4*# + 1] && PrimeQ[8*# + 3] &] (* T. D. Noe, Nov 07 2011 *)
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CROSSREFS
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Cf. A001122, A005098, A005124.
Sequence in context: A212979 A114961 A219045 * A178508 A123834 A064629
Adjacent sequences: A199424 A199425 A199426 * A199428 A199429 A199430
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KEYWORD
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nonn
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AUTHOR
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Martin Renner, Nov 06 2011
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STATUS
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approved
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