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A139057
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Primes of the form (k!-3)/3.
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12
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OFFSET
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1,1
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COMMENTS
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Numbers k for which (k! - 3)/3 is prime see A139056.
a(8) is 180 decimal digits long. See formula for more terms. - Derek Orr, Mar 28 2014
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LINKS
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FORMULA
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MATHEMATICA
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a = {}; Do[If[PrimeQ[(-3 + n!!)/3], AppendTo[a, [(-3 + n!!)/3]], {n, 1, 1000}]; a
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PROG
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(PARI) for(n=1, 1000, if(floor(n!/3-1)==n!/3-1, if(ispseudoprime(n!/3-1), print(n!/3-1)))) \\ Derek Orr, Mar 28 2014
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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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Definition corrected by Derek Orr, Mar 28 2014
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STATUS
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approved
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