A068005 - OEIS

A068005

Numbers n such that n*sigma(n) > phi(n)*prime(n).

2, 3, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 28, 30, 36, 40, 42, 48, 50, 54, 56, 60, 66, 70, 72, 78, 80, 84, 90, 96, 100, 102, 108, 114, 120, 126, 132, 138, 140, 144, 150, 156, 160, 162, 168, 174, 180, 186, 192, 198, 204, 210, 216, 220, 222, 228, 234, 240, 252, 264

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

OFFSET

1,1

LINKS

Ivan Neretin, Table of n, a(n) for n = 1..10000

MATHEMATICA

Select[Range@265, #*DivisorSigma[1, #] > EulerPhi[#]*Prime[#] &] (* Ivan Neretin, Dec 28 2016 *)

CROSSREFS

Sequence in context: A371925 A084925 A045718 * A055721 A064376 A283808

Adjacent sequences: A068002 A068003 A068004 * A068006 A068007 A068008

KEYWORD

easy,nonn

AUTHOR

Benoit Cloitre, Mar 22 2002

STATUS

approved