A055163 - OEIS

A055163

(n - Phi(n)) | Sigma(n) for composite n.

6, 10, 14, 22, 26, 34, 38, 46, 58, 62, 74, 82, 86, 94, 99, 106, 118, 122, 134, 142, 146, 158, 166, 168, 178, 187, 194, 202, 206, 214, 218, 226, 254, 262, 274, 278, 298, 302, 314, 326, 334, 346, 358, 362, 382, 386, 394, 398, 422, 446, 454, 458, 466, 478, 482

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..1000

MATHEMATICA

Do[ If[ !PrimeQ[ n ], If[ Mod[ DivisorSigma[ 1, n ], n-EulerPhi[ n ] ] == 0, Print[ n ] ], {n, 1, 500} ]

Select[Range[500], CompositeQ[#]&&Divisible[DivisorSigma[1, #], #-EulerPhi[ #]]&] (* Harvey P. Dale, May 16 2016 *)

CROSSREFS

Sequence in context: A080784 A072978 A369966 * A342192 A119431 A207574

Adjacent sequences: A055160 A055161 A055162 * A055164 A055165 A055166

KEYWORD

easy,nonn

AUTHOR

Robert G. Wilson v, Jun 30 2000

STATUS

approved