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A064278
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Numbers n such that n! + prime(n) is prime.
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7
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1, 2, 3, 4, 5, 6, 9, 11, 17, 18, 25, 31, 40, 96, 174, 193, 204, 269, 523, 650, 659, 797, 1437, 1862, 2515, 4983, 5557
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OFFSET
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1,2
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COMMENTS
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The numbers corresponding to 2515 and 4983 are probable primes. [Farideh Firoozbakht, Oct 15 2009]
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LINKS
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EXAMPLE
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n=5: 5! = 120 and prime(5) = 11, 120+11 = 131.
6 is listed because 6!+prime(6) = 720+13 = 733 is prime.
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MATHEMATICA
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Do[ If[ PrimeQ[ n! + Prime[ n ] ], Print[ n ] ], {n, 1, 700} ]
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PROG
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(PARI) for(n=1, 100, if (isprime(n!+prime(n)), print1(n, ", ")))
(Magma) [n: n in [1..200] | IsPrime(Factorial(n)+ NthPrime(n))]; // Vincenzo Librandi, Mar 05 2015
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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More terms from John Sillcox (JMS21187(AT)aol.com), Apr 05 2003
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STATUS
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approved
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