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A015733 d(n) does not divide phi(n). 5
2, 4, 6, 12, 14, 16, 20, 22, 25, 27, 32, 36, 38, 42, 44, 46, 48, 50, 54, 60, 62, 64, 66, 68, 75, 80, 81, 86, 92, 94, 96, 100, 112, 114, 116, 118, 121, 132, 134, 138, 142, 144, 150, 154, 158, 160, 162, 164, 166, 180, 186, 188, 189, 192, 196, 200, 204 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Enrique Pérez Herrero and Michael De Vlieger, Table of n, a(n) for n = 1..18157 (first 2000 terms from Enrique Pérez Herrero)

FORMULA

A000010(n) mod A000005(n)>0. [Paolo P. Lava, Jan 31 2013]

MAPLE

with(numtheory);

A015733:=proc(q)

local n; for n from 1 to q do if (phi(n) mod tau(n))>0 then print(n); fi;

od; end:

A015733(10000000); # Paolo P. Lava, Jan 31 2013

MATHEMATICA

Select[Range[204], ! Divisible[EulerPhi[#], DivisorSigma[0, #]] &]

CROSSREFS

Cf. A020491 (d(n) does divide phi(n)).

Sequence in context: A056371 A271822 A067874 * A247460 A023187 A061012

Adjacent sequences:  A015730 A015731 A015732 * A015734 A015735 A015736

KEYWORD

nonn

AUTHOR

Robert G. Wilson v

STATUS

approved

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Last modified February 26 15:26 EST 2021. Contains 341632 sequences. (Running on oeis4.)