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A063824 Numbers n such that sigma(phi(n^3)) = phi(sigma(n^3)). 0
1, 9, 81, 225, 2025, 5625, 50625, 65025, 585225, 1625625 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..10.

MATHEMATICA

Select[Range[3000000], DivisorSigma[1, EulerPhi[#^3]]==EulerPhi[ DivisorSigma[1, #^3]]&] (* Harvey P. Dale, Mar 23 2012 *)

PROG

(PARI) for(n=1, 10^9, if(sigma(eulerphi(n^3))==eulerphi(sigma(n^3)), print(n)))

CROSSREFS

Sequence in context: A207369 A208014 A208556 * A207560 A207415 A207020

Adjacent sequences:  A063821 A063822 A063823 * A063825 A063826 A063827

KEYWORD

nonn

AUTHOR

Jason Earls, Aug 20 2001

STATUS

approved

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Last modified July 1 22:23 EDT 2022. Contains 354984 sequences. (Running on oeis4.)