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A071181
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Number of k such that phi(k) divides phi(n).
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6
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2, 2, 5, 5, 9, 5, 9, 9, 9, 9, 7, 9, 19, 9, 14, 14, 20, 9, 13, 14, 19, 7, 7, 14, 16, 19, 13, 19, 11, 14, 13, 20, 16, 20, 34, 19, 31, 13, 34, 20, 30, 19, 13, 16, 34, 7, 7, 20, 13, 16, 27, 34, 11, 13, 30, 34, 31, 11, 7, 20, 37, 13, 31, 27, 51, 16, 13, 27, 14, 34, 9, 34, 63, 31, 30, 31
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OFFSET
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1,1
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LINKS
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FORMULA
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PROG
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(PARI) for(n=1, 100, print1(sum(i=1, 1000, if(eulerphi(n)%eulerphi(i), 0, 1)), ", "))
(Scheme)
;; A naive implementation requiring precomputed A057826:
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CROSSREFS
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KEYWORD
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easy,nonn
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AUTHOR
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STATUS
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approved
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