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A066576
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Composite Euclid numbers: numbers of the form p# + 1, where p# denotes the primorial of the prime p.
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3
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30031, 510511, 9699691, 223092871, 6469693231, 7420738134811, 304250263527211, 13082761331670031, 614889782588491411, 32589158477190044731, 1922760350154212639071, 117288381359406970983271
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OFFSET
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1,1
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COMMENTS
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30031 appears in Wells's "Curious and Interesting Numbers" as the smallest composite number of the form p# + 1.
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REFERENCES
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David Wells, "The Penguin Dictionary of Curious and Interesting Numbers," Revised Edition, Penguin Books, London, England, 1997, page 166.
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LINKS
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MATHEMATICA
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Do[c = Product[ Prime[i], {i, 1, n}] + 1; If[ !PrimeQ[c], Print[c]], {n, 1, 20} ]
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PROG
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(Magma) [a: n in [2..19]| not IsPrime(a) where a is 1+&*[NthPrime(k):k in [1..n]]]; // Marius A. Burtea, Feb 18 2020
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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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STATUS
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approved
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