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A092023
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a(n) is the smallest number m such that m has n distinct prime divisors and if p is a prime divisor of m then p*m - 1 is prime.
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3
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2, 6, 30, 420, 32550, 410970, 55137810, 1350063330, 30644204010, 9396949341780, 6805591029957720
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OFFSET
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1,1
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COMMENTS
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2004 has this property, i.e., 2004 = 2^2*3*167, the three numbers 2*2004-1,3*2004-1 and 167*2004-1 are primes. But 2004 is not in the sequence because 2004 is not the smallest number with such property.
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LINKS
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EXAMPLE
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a(7) = 55137810 because 55137810 = 2*3*5*7*13*19*1063 and all the seven numbers 2*55137810-1, 3*55137810-1, 5*55137810-1, 7*55137810-1, 13*55137810-1, 19*55137810-1 and 1063*55137810-1 are prime numbers and 55137810 is the smallest number m with such property.
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CROSSREFS
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KEYWORD
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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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