A058652 Squarefree n such that sigma(phi(n)) = phi(sigma(n)).

1, 29262, 114630, 160986, 179562, 252978, 502878, 528954, 780258, 908070, 1080906, 1826454, 2460786, 2870142, 3934686, 5086722, 5493030, 6001206, 6183078, 6621270, 6668634, 8808234, 9298110, 9752190, 10479282, 11707518, 12263334, 12928254, 13513278

Offset: 1

Author

Robert G. Wilson v, Dec 26 2000

Keywords

• nonn

Links

• Donovan Johnson, Table of n, a(n) for n = 1..500

Crossrefs

Cf. A033632.

Programs

Mathematica

Select[ Range[ 10^7 ], DivisorSigma[ 1, EulerPhi[ # ] ] == EulerPhi[ DivisorSigma[ 1, # ] ] && Union[ Transpose[ FactorInteger[ # ] ] [ [ 2 ] ] ] == {1} & ]

Extensions

Prepended missing a(1)=1, Donovan Johnson, Mar 03 2012.