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A140077
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Numbers n such that n and n+1 have 3 distinct prime factors.
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8
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230, 285, 429, 434, 455, 494, 560, 594, 609, 615, 644, 645, 650, 665, 740, 741, 759, 804, 805, 819, 825, 854, 860, 884, 902, 935, 945, 969, 986, 987, 1001, 1014, 1022, 1034, 1035, 1044, 1064, 1065, 1070, 1085, 1104, 1105, 1130, 1196, 1209, 1220, 1221
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OFFSET
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1,1
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LINKS
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Table of n, a(n) for n=1..47.
D. A. Goldston, S. W. Graham, J. Pintz, 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]] == 3 && Length[FactorInteger[n + 1]] == 3, AppendTo[a, n]], {n, 1, 100000}]; a (*Artur Jasinski*)
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CROSSREFS
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Cf. A074851, A140078, A140079 .
Sequence in context: A177826 A122269 A171666 * A215217 A211711 A211716
Adjacent sequences: A140074 A140075 A140076 * A140078 A140079 A140080
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KEYWORD
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nonn
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AUTHOR
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Artur Jasinski, May 07 2008
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STATUS
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approved
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