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A110601
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phi(n)*tau(n)^2, where phi is Euler's totient function and tau(n) is the number of divisors of n.
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0
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1, 4, 8, 18, 16, 32, 24, 64, 54, 64, 40, 144, 48, 96, 128, 200, 64, 216, 72, 288, 192, 160, 88, 512, 180, 192, 288, 432, 112, 512, 120, 576, 320, 256, 384, 972, 144, 288, 384, 1024, 160, 768, 168, 720, 864, 352, 184, 1600, 378, 720, 512, 864, 208, 1152, 640
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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REFERENCES
| S. Porubsky, Problem E2351, Amer. Math. Monthly, 80, 1973, p. 436.
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EXAMPLE
| a(4)=18 because phi(4)=2 and tau(4)=3.
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MAPLE
| with(numtheory): a:=n->phi(n)*tau(n)^2: seq(a(n), n=1..70);
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MATHEMATICA
| Table[EulerPhi[n]DivisorSigma[0, n]^2, {n, 60}] (* From Harvey P. Dale, Nov 29 2011 *)
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CROSSREFS
| Cf. A062355, A035116.
Sequence in context: A145779 A144178 A075558 * A107926 A174741 A070213
Adjacent sequences: A110598 A110599 A110600 * A110602 A110603 A110604
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KEYWORD
| nonn,mult
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AUTHOR
| Emeric Deutsch (deutsch(AT)duke.poly.edu), Jul 29 2005
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