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Search: id:A065819
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| A065819 |
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4*EulerPhi[n] = 3*DivisorSigma[1,n]. |
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+0
5
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| 7, 209, 10013, 11687, 12857, 17537, 27577, 28067, 700321, 770431, 1321189, 1542281, 1681861, 1963039, 2282641, 2313961, 2664259, 3308041, 3709057, 3859207, 3929761, 4315751, 4380541, 4561381, 5193001, 5331001, 5576519
(list; graph; listen)
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OFFSET
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1,1
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LINKS
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Harry J. Smith, Table of n, a(n) for n=1,...,65
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EXAMPLE
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For m=10013, Phi[m]=8640,Sigma[m]=11520, 34560=4*Phi=3*Sigma.
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MATHEMATICA
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Do[s = 4*EulerPhi[n]-3*DivisorSigma[1, n]; If[Equal[s, 0], Print[n]], {n, 1, 10000000}]
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PROGRAM
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(PARI) { n=0; for (m=1, 10^9, if (4*eulerphi(m) == 3*sigma(m), write("b065819.txt", n++, " ", m); if (n==65, return)) ) } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), Oct 31 2009]
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CROSSREFS
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Cf. A000010, A000203, A062699
Sequence in context: A124988 A128680 A157775 this_sequence A061028 A045760 A046033
Adjacent sequences: A065816 A065817 A065818 this_sequence A065820 A065821 A065822
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KEYWORD
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easy,nonn
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AUTHOR
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Labos E. (labos(AT)ana.sote.hu), Nov 23 2001
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