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A066154 Numbers k such that EulerPhi(k) = sigma(k) - sigma(k-1). 1
574, 3496, 148708, 380276, 604504, 703402, 1223194, 1961218, 2375854, 5153085, 13182476, 15089116, 15624820, 18503524, 19402515, 22352968, 27366118, 41377798, 42917332, 51062116, 58911736, 60113914, 74657636, 75018856 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Harry J. Smith, Table of n, a(n) for n = 1..29

EXAMPLE

EulerPhi(574) = 240 = 1008 - 768 = sigma(574) - sigma(573).

MATHEMATICA

Select [Range[1, 10^7], EulerPhi[ # ] == DivisorSigma[1, # ] - DivisorSigma[1, # - 1] & ]

PROG

(PARI) { n=0; for (m=2, 10^9, if (eulerphi(m) == sigma(m) - sigma(m - 1), write("b066154.txt", n++, " ", m); if (n==100, return)) ) } \\ Harry J. Smith, Feb 03 2010

CROSSREFS

Sequence in context: A090495 A092291 A158371 * A321052 A291133 A027456

Adjacent sequences:  A066151 A066152 A066153 * A066155 A066156 A066157

KEYWORD

nonn

AUTHOR

Joseph L. Pe, Dec 13 2001

EXTENSIONS

a(11)-a(24) from Harry J. Smith, Feb 03 2010

STATUS

approved

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Last modified October 22 21:58 EDT 2020. Contains 337962 sequences. (Running on oeis4.)