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A280907
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Least k such that cototient(k) has exactly n distinct prime factors.
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0
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OFFSET
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1,1
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COMMENTS
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LINKS
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EXAMPLE
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a(1) = 4 because 4 - phi(4) = 2.
a(2) = 10 because 10 - phi(10) = 6 = 2 * 3.
a(3) = 42 because 42 - phi(42) = 30 = 2 * 3 * 5.
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PROG
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(PARI) a(n) = {my(k = 2); while(omega(k-eulerphi(k)) != n, k++); k; }
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CROSSREFS
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KEYWORD
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nonn,more
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AUTHOR
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STATUS
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approved
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