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A052215
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a(n) = smallest number m such that m and m+1 are the product of exactly n distinct primes.
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11
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2, 14, 230, 7314, 378014, 11243154, 965009045, 65893166030, 5702759516090, 605247139068494, 78971815814237709, 22593106657425552170
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OFFSET
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1,1
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COMMENTS
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Prime factors may not be repeated in m and m+1. The difference between this sequence and A093548 is that in the latter, prime factors may be repeated. So the present sequence imposes more stringent conditions than A093548, hence a(n) >= A093548(n). - N. J. A. Sloane, Nov 21 2015
a(12) confirmed to be the upper limit of the range above. - Bert Dobbelaere, Jun 27 2019
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LINKS
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EXAMPLE
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14 and 15 are both the product of 2 primes.
230 is the 3rd entry because we have (230=2*5*23, 231=3*7*11).
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CROSSREFS
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KEYWORD
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hard,nice,nonn,more
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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