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A065819
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4*phi(n) = 3*sigma(n).
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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; refs; listen; history; internal format)
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OFFSET
| 1,1
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LINKS
| Harry J. Smith, Table of n, a(n) for n = 1..65
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EXAMPLE
| For m=10013, phi(m)=8640, sigma(m)=11520, 34560=4*phi=3*sigma.
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MATHEMATICA
| Do[s = 4*EulerPhi[n]-3*DivisorSigma[1, n]; If[Equal[s, 0], Print[n]], {n, 1, 10000000}]
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PROG
| (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
| Cf. A000010, A000203, A062699.
Sequence in context: A177813 A178022 A157775 * A061028 A012862 A045760
Adjacent sequences: A065816 A065817 A065818 * A065820 A065821 A065822
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KEYWORD
| nonn
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AUTHOR
| Labos E. (labos(AT)ana.sote.hu), Nov 23 2001
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