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A265121
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Integers n such that n*3^n + 2 is prime.
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1
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0, 1, 3, 5, 11, 15, 17, 153, 169, 273, 317, 373, 923, 1403, 1969, 2349, 7809, 10313, 12291, 24865
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OFFSET
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1,3
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COMMENTS
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Initial corresponding primes are 2, 5, 83 and 1217.
How do this sequence and A006552 compare asymptotically?
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LINKS
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Table of n, a(n) for n=1..20.
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EXAMPLE
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a(3) = 3 because 3^3 * 3 + 2 = 83 is prime.
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MATHEMATICA
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Select[Range[0, 10000], PrimeQ[# 3^# + 2] &] (* Vincenzo Librandi, Dec 02 2015 *)
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PROG
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(PARI) for(n=0, 1e6, if(ispseudoprime(3^n*n + 2), print1(n, ", ")));
(MAGMA) [n: n in [0..400] | IsPrime(n*3^n+2)]; // Vincenzo Librandi, Dec 02 2015
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CROSSREFS
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Cf. A006552, A036290, A182373.
Sequence in context: A316092 A302590 A316151 * A281575 A105772 A244520
Adjacent sequences: A265118 A265119 A265120 * A265122 A265123 A265124
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KEYWORD
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nonn,hard,more
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AUTHOR
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Altug Alkan, Dec 01 2015
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EXTENSIONS
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a(1) = 0 added by Vincenzo Librandi, Dec 02 2015
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STATUS
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approved
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