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A068488
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m for which p(m) is the least prime dividing #p(n) + 1, i.e., primorial n-th prime augmented by 1 (A005234).
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1
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2, 4, 11, 47, 344, 17, 8, 69, 66, 67, 8028643011, 42, 18, 39, 162, 21, 59, 48, 2311331257, 179, 369, 2477, 23289, 32, 172011, 75668, 342, 35, 28757, 356411, 243, 297, 152
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OFFSET
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1,1
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COMMENTS
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Since #P34 + 1 has two rather large factors, we need the number of primes less than or equal to 678279959005528882498681487.
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LINKS
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FORMULA
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MATHEMATICA
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Do[ Print[ PrimePi[ FactorInteger[ Product[ Prime[k], {k, 1, n}] + 1] [[1, 1]]]], {n, 1, 20} ]
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CROSSREFS
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KEYWORD
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nonn,hard,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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