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A139203
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Numbers k such that (k!-8)/8 is prime.
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3
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4, 6, 8, 10, 11, 16, 19, 47, 66, 183, 376, 507, 1081, 1204, 12111, 23181
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OFFSET
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1,1
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COMMENTS
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LINKS
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MAPLE
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a:=proc(n) if isprime((1/8)*factorial(n)-1)=true then n else end if end proc: seq(a(n), n=4..550); # Emeric Deutsch, May 07 2008
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MATHEMATICA
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a = {}; Do[If[PrimeQ[(n! - 8)/8], Print[a]; AppendTo[a, n]], {n, 1, 300}]; a
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CROSSREFS
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Cf. n!/m-1 is a prime: A002982, A082671, A139056, A139199-A139205; n!/m+1 is a prime: A002981, A082672, A089085, A139061, A139058, A139063, A139065, A151913, A137390, A139071 (1<=m<=10).
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KEYWORD
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hard,more,nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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