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A227627
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Numbers n such that F(5*n)/(5*F(n)) is prime, where F(k) is the k-th Fibonacci number.
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1
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2, 3, 5, 7, 13, 25, 29, 37, 47, 67, 457, 2309, 2383, 4133, 5023, 8059
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OFFSET
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1,1
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COMMENTS
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Except for n = 25, all other terms n are primes. Conjecture: this sequence is infinite. - Thomas Ordowski, Jul 18 2013
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LINKS
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MATHEMATICA
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Select[Range[1000], PrimeQ[Fibonacci[5*#]/Fibonacci[#]/5]&]
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PROG
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CROSSREFS
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KEYWORD
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nonn,more,hard
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AUTHOR
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STATUS
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approved
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