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Search: id:A140078
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| A140078 |
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Numbers n such that n and n+1 have 4 distinct prime factors. |
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+0
6
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| 7314, 8294, 8645, 9009, 10659, 11570, 11780, 11934, 13299, 13629, 13845, 14420, 15105, 15554, 16554, 16835, 17204, 17390, 17654, 17765, 18095, 18290, 18444, 18920, 19005, 19019, 19095, 19227, 20349, 20405, 20769, 21164, 21489, 21735
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OFFSET
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1,1
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COMMENT
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For numbers n such that n and n+1 have k distinct prime factors see:
k=2 A074851
k=3 A140077
k=4 A140078
k=5 A140079
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LINKS
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D. A. Goldston, S. W. Graham, J. Pintz and C. Y. Yildirim., Small gaps between almost primes, the parity problem and some conjectures of Erdos on consecutive integers.
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MATHEMATICA
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a = {}; Do[If[Length[FactorInteger[n]] == 4 && Length[FactorInteger[n + 1]] == 4, AppendTo[a, n]], {n, 1, 100000}]; a (*Artur Jasinski*)
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CROSSREFS
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Cf. A074851, A140077, A140079 .
Sequence in context: A152502 A031799 A116248 this_sequence A117799 A097696 A128478
Adjacent sequences: A140075 A140076 A140077 this_sequence A140079 A140080 A140081
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KEYWORD
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nonn
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AUTHOR
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Artur Jasinski (grafix(AT)csl.pl), May 07 2008
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