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Search: id:A123074
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| A123074 |
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Number of ordered triples of primes (p,q,r) such that pqr = n. |
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+0
2
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| 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 3, 0, 0, 0, 0, 0, 3, 0, 3, 0, 0, 0, 0, 0, 0, 1, 3, 0, 6, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 6, 0, 3, 3, 0, 0, 0, 0, 3, 0, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 6, 0, 3, 0, 6, 0, 0, 0, 0, 3, 3, 0, 6, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 0, 0, 0, 3, 3, 0, 0, 6, 0, 0, 6
(list; graph; listen)
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OFFSET
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1,12
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COMMENT
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a(p^3) = 1, a(p^2 q) = 3, a(pqr) = 6, otherwise a(n) = 0.
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MATHEMATICA
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Join[{0}, Table[e=Sort[Transpose[FactorInteger[n]][[2]]]; Which[e=={3}, 1, e=={1, 2}, 3, e=={1, 1, 1}, 6, True, 0], {n, 2, 150}]] - T. D. Noe (noe(AT)sspectra.com), Sep 29 2006
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CROSSREFS
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Cf. A123073, A014612.
Sequence in context: A059484 A035678 A094518 this_sequence A095269 A111417 A007271
Adjacent sequences: A123071 A123072 A123073 this_sequence A123075 A123076 A123077
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KEYWORD
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nonn
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AUTHOR
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njas and T. D. Noe, Sep 29 2006
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EXTENSIONS
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More terms from T. D. Noe (noe(AT)sspectra.com), Sep 29 2006
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