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A134753
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Numbers n such that 3^(2*n-1) + 2 is prime.
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2
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1, 2, 8, 32, 62, 70, 118, 122, 158, 182, 196, 566, 752, 3602, 21896, 22768, 53072
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OFFSET
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1,2
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COMMENTS
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With: f(n)=3^(2n-1)+2, the non-primality of f(n) is settled when:
if 2 does not divide n, 5 divides f(n) (n>1)
if 3 divides n, 7 divides f(n)
if 5 divides n-4, 11 divides f(n)
if 14 divides n-2, 29 divides f(n)
if 15 divides n-5, 31 divides f(n).
(End)
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REFERENCES
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LINKS
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FORMULA
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MATHEMATICA
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MaxVal = 1000;
dataA134753=Select[Select[Range[MaxVal], #<3||Mod[#, 2]==0&&Mod[#, 3]!=0&&Mod[#, 5]!=4&&Mod[#, 14]!=2&&Mod[#, 15]!=5&], PrimeQ[3^(2*#-1)+2]&]
A134753[n_Integer] := dataA134753[[n]] /; (n > 0 && n <= Length[dataA134753])
(End)
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PROG
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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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