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%I #23 Nov 25 2014 16:30:02
%S 2,3,5,7,13,25,29,37,47,67,457,2309,2383,4133,5023,8059
%N Numbers n such that F(5*n)/(5*F(n)) is prime, where F(k) is the k-th Fibonacci number.
%C Except for n = 25, all other terms n are primes. Conjecture: this sequence is infinite. - _Thomas Ordowski_, Jul 18 2013
%t Select[Range[1000],PrimeQ[Fibonacci[5*#]/Fibonacci[#]/5]&]
%o (PARI) is(n)=ispseudoprime(fibonacci(5*n)/fibonacci(n)/5) \\ _Charles R Greathouse IV_, Nov 25 2014
%Y Cf. A227576, A088545, A000045, A001605.
%K nonn,more,hard
%O 1,1
%A _Vaclav Kotesovec_, Jul 18 2013
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