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Lowest outliers for A057660.
3

%I #15 May 31 2019 11:33:53

%S 1,4,6,12,24,30,60,120,180,210,360,420,840,1260,2520,4620,9240,13860,

%T 27720,55440,60060,120120,180180,360360,720720,1441440,1801800,

%U 2042040,3063060,6126120,12252240,24504480,30630600,36756720,38798760

%N Lowest outliers for A057660.

%C A057660(n) is a multiplicative function bounded above by n*(n-1)+1, which is reached whenever n is 1 or prime. These numbers are the n such that the ratio between A057660(n) and the upper bound reaches a record low.

%C Motivated by _Daniel Forgues_'s conjecture that this sequence consists of 4 and A051451.

%C A subsequence of A025487.

%H Charlie Neder, <a href="/A308471/b308471.txt">Table of n, a(n) for n = 1..215</a>

%e A057660(60060)/(60060*60059+1) = 1211716737/3607143541 ~ 0.3359214, and every number less than 60060 has a ratio > 0.34, so 60060 is in this sequence.

%Y Cf. A057660, A025487, A051451.

%K nonn

%O 1,2

%A _Charlie Neder_, May 29 2019