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A077006 Numbers n such that sigma(n)/n >= sigma(m)/m for all m <= n. 3

%I

%S 1,2,4,6,12,24,36,48,60,120,180,240,360,720,840,1260,1680,2520,5040,

%T 10080,15120,25200,27720,55440,110880,166320,277200,332640,360360,

%U 554400,665280,720720,1441440,2162160,3603600,4324320,7207200,8648640,10810800,21621600

%N Numbers n such that sigma(n)/n >= sigma(m)/m for all m <= n.

%e 360360 is included in this sequence (but not in A004394) because its abundancy (sigma(n)/n = 48/11) is the same as that of the previous record holder (namely 332640). - _Gerard P. Michon_, May 20 2009

%t abund[n_] := abund[n] = DivisorSigma[1, n]/n; ok[n_] := (r = True; m = 1; While[m <= n, If[abund[n] < abund[m], r = False; Break[]]; m++]; r); n = 1; A077006 = {}; While[n < 10^6, If[ok[n], Print[n]; AppendTo[ A077006, n]]; n++]; A077006 (* _Jean-Fran├žois Alcover_, Dec 12 2011 *)

%Y Almost same as A004394.

%K nice,nonn

%O 1,2

%A _Mike Speciner_, Oct 15 2003

%E a(31)-a(40) from _Jon E. Schoenfield_, Mar 31 2018

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Last modified October 18 22:16 EDT 2019. Contains 328211 sequences. (Running on oeis4.)