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Search: id:A068489
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| A068489 |
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m for which p(m) is the least prime dividing #p(n) - 1, i.e. one less than primorial n-th prime (A057588). |
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+0
2
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| 3, 10, 5, 343, 3248, 18, 16, 12, 22, 20324, 50
(list; graph; listen)
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OFFSET
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2,1
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COMMENT
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Since #P13 -1 is a prime, see A006794, we need the number of primes less than or equal to #P13 -1. The sequence continues 13120,43,8481,1200361259,196,38,10326732314,65,38,34,
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LINKS
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Hisanori Mishima, Factorization results #Pn (Primorial) - 1
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FORMULA
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PrimePi(A057713)
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MATHEMATICA
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Do[ Print[ PrimePi[ FactorInteger[ Product[ Prime[k], {k, 1, n}] - 1] [[1, 1]]]], {n, 2, 22} ]
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CROSSREFS
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Cf. A068488.
Sequence in context: A033478 A111127 A140948 this_sequence A088337 A087397 A033152
Adjacent sequences: A068486 A068487 A068488 this_sequence A068490 A068491 A068492
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KEYWORD
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hard,more,nonn
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AUTHOR
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Lekraj Beedassy (blekraj(AT)yahoo.com), Mar 11 2002
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EXTENSIONS
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Edited and extended by Robert G. Wilson v (rgwv(AT)rgwv.com), Mar 12 2002
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