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Search: id:A062823
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| A062823 |
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Quotient of number of divisors of totient of n and that of n is an integer. |
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+0
1
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| 1, 3, 7, 11, 13, 14, 15, 19, 22, 23, 25, 28, 29, 31, 35, 39, 41, 43, 44, 46, 47, 50, 53, 55, 56, 59, 61, 62, 67, 68, 70, 71, 73, 77, 78, 79, 82, 83, 86, 87, 88, 89, 91, 92, 93, 94, 95, 97, 99, 103, 107, 109, 110, 111, 112, 113, 115, 117, 118, 119, 122, 124, 127, 129, 131
(list; graph; listen)
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OFFSET
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0,2
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LINKS
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Harry J. Smith, Table of n, a(n) for n=0,...,1000
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FORMULA
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a(n)=d(Phi[n])/d(n), where d(n)=A000005(n) d(Phi[n])=DivisorSigma[0, EulerPhi[n]]=A000005[A000010(n)]
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EXAMPLE
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For n={3,11,29} Phi(n)={2,10,28}, d(Phi[n])={2,4,6},d(n)=2, quotient={1,2,3}.
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PROGRAM
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(PARI) { n=-1; for (m=1, 10^9, if ((numdiv(eulerphi(m))/numdiv(m))%1.0 == 0, write("b062823.txt", n++, " ", m); if (n==1000, break)) ) } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), Aug 11 2009]
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CROSSREFS
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A000005, A000010.
Sequence in context: A055050 A096346 A104534 this_sequence A031466 A045062 A111068
Adjacent sequences: A062820 A062821 A062822 this_sequence A062824 A062825 A062826
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KEYWORD
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nonn
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AUTHOR
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Labos E. (labos(AT)ana.sote.hu), Jul 20 2001
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