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A116008 n + sigma(n) + phi(n) is a cube. 2
8, 120, 496, 914, 3940, 4055, 4252, 8129, 12092, 13779, 14291, 28394, 29948, 41200, 49469, 55255, 58538, 68459, 104512, 114844, 119303, 135068, 135074, 152177, 162127, 170666, 176705, 190595, 220714, 253888, 270916, 285664 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..32.

EXAMPLE

914 + sigma(914) + phi(914) = 14^3.

MATHEMATICA

Select[Range[300000], IntegerQ[Surd[#+DivisorSigma[1, #]+EulerPhi[#], 3]]&] (* Harvey P. Dale, May 02 2019 *)

PROG

(PARI) isok(n) = ispower (n + sigma(n) + eulerphi(n), 3); \\ Michel Marcus, Jan 26 2014

CROSSREFS

Cf. A116007, A116009.

Sequence in context: A267752 A318009 A228752 * A086302 A053129 A249641

Adjacent sequences:  A116005 A116006 A116007 * A116009 A116010 A116011

KEYWORD

nonn

AUTHOR

Giovanni Resta, Feb 13 2006

STATUS

approved

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Last modified September 30 11:00 EDT 2022. Contains 357105 sequences. (Running on oeis4.)