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A053982
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Numbers n such that 1 + product of first n composite numbers is prime.
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1
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1, 3, 7, 11, 16, 22, 39, 76, 116, 139, 149, 169, 179, 220, 372, 429, 1216
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OFFSET
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1,2
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LINKS
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MATHEMATICA
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Composite[n_Integer] := (k = n + PrimePi[n] + 1; While[k - PrimePi[k] - 1 != n, k++ ]; k); Do[ If[ PrimeQ[ Product[ Composite[k], {k, 1, n} ] + 1], Print[ n ] ], {n, 1, 430} ]
Position[FoldList[Times, Select[Range[1500], CompositeQ]], _?(PrimeQ[#+1]&)]//Flatten (* Harvey P. Dale, Dec 20 2022 *)
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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 Jeppe Stig Nielsen, Apr 16 2000 (terms from 76 on correspond to probable primes)
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STATUS
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approved
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