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A116007 n + sigma(n) + phi(n) is a fourth power. 2
81, 18904, 176705, 204576, 534160, 1362561, 1366633, 1698256, 1866768, 2034576, 2523024, 2909656, 3380856, 7217649, 9439473, 9454609, 11197696, 12866040, 29508673, 32363424, 34142545, 34682089, 46426160, 46448824, 53445456 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..25.

EXAMPLE

81 + sigma(81) + phi(81) = 4^4.

PROG

(PARI) isok(n) = ispower(n + sigma(n) + eulerphi(n), 4); \\ Michel Marcus, Jan 25 2014

CROSSREFS

Cf. A116008, A116009.

Sequence in context: A243007 A143653 A222621 * A013829 A100533 A088063

Adjacent sequences:  A116004 A116005 A116006 * A116008 A116009 A116010

KEYWORD

nonn

AUTHOR

Giovanni Resta, Feb 13 2006

EXTENSIONS

a(15)-a(25) from Donovan Johnson, Jul 02 2010

STATUS

approved

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Last modified August 8 12:09 EDT 2022. Contains 356009 sequences. (Running on oeis4.)