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A126090
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a(1)=1. a(n) = the number of terms among {a(1),a(2),...a(n-1)} which are coprime to exactly one distinct prime dividing n.
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1
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1, 1, 2, 2, 4, 3, 6, 3, 5, 5, 10, 6, 12, 7, 8, 5, 16, 8, 18, 13, 7, 11, 22, 10, 17, 14, 18, 16, 28, 9, 30, 11, 12, 20, 11, 16, 36, 22, 12, 23, 40, 14, 42, 28, 19, 29, 46, 22, 39, 28, 15, 33, 52, 28, 16, 29, 17, 36, 58, 20, 60, 38, 25, 22, 15, 23, 66, 43, 23, 20, 70, 37, 72, 45
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OFFSET
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1,3
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LINKS
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EXAMPLE
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There are 6 terms among the first 11 terms of the sequence which are each coprime to exactly one distinct prime dividing 12 (a(3)=2, a(4)=2, a(5)=4, a(6)=3, a(8)=3 and a(11)=10). So a(12) = 6.
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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