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A092584 Numbers n such that sigma(phi(n)) = phi(sigma(n)) mod n, that is, A033632(n)/n is an integer. 7
1, 5, 9, 157, 225, 242, 516, 729, 3872, 13932, 14406, 17672, 18225, 20124, 21780, 29262, 29616, 45996, 65025, 76832, 92778, 95916, 106092, 106308, 114630, 114930, 121872, 125652, 140130, 140625, 145794, 149124, 160986, 179562, 185100, 234876 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..36.

EXAMPLE

Includes but is not identical with A033632.

Below 10^7 only a(2)=5 and a(4)=157 give A033632(n)/n nonzero.

PROG

(PARI) is(n)=sigma(eulerphi(n))==Mod(eulerphi(sigma(n)), n) \\ Charles R Greathouse IV, Nov 27 2013

CROSSREFS

Cf. A033632, A092585-A092588, A065395.

Sequence in context: A222583 A222374 A097397 * A145400 A002657 A046093

Adjacent sequences:  A092581 A092582 A092583 * A092585 A092586 A092587

KEYWORD

nonn

AUTHOR

Labos Elemer, Mar 01 2004

STATUS

approved

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Last modified January 16 03:30 EST 2019. Contains 319184 sequences. (Running on oeis4.)