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A135060 a(n) is the smallest number m for which none of the first n multiples of m has twice as many divisors as m.

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%I A135060 #14 Mar 17 2022 01:05:02
%S A135060 1,2,6,12,60,120,840,840,2520,2520,27720,55440,720720,720720,1081080,
%T A135060 2162160,36756720,36756720,698377680,698377680,698377680,698377680,
%U A135060 16062686640,48188059920,160626866400,160626866400,160626866400
%N A135060 a(n) is the smallest number m for which none of the first n multiples of m has twice as many divisors as m.
%C A135060 a(n) is smallest integer m such that A129902(m)/m > n.
%C A135060 Conjecture: every number in this sequence is also in A002182. [_J. Lowell_ disproved this conjecture at a(24) = 48188059920. - _Ray Chandler_]
%C A135060 The conjecture that every term is a multiple of the preceding term is disproved at n = 15; a(15) = 1081080, which is not a multiple of a(14) = 720720. - _J. Lowell_, Jun 06 2008
%H A135060 Ray Chandler, <a href="/A135060/b135060.txt">Table of n, a(n) for n = 1..130</a>.
%e A135060 60 is not a(6) because 60 has 12 divisors and 60*6=360 has 12*2=24 divisors.
%K A135060 nonn
%O A135060 1,2
%A A135060 _J. Lowell_, Feb 11 2008, Jul 08 2008, Jul 14 2008
%E A135060 More terms from _J. Lowell_, May 13 2009
%E A135060 Inequality in the comment corrected and a(16) added by _R. J. Mathar_, Nov 04 2009
%E A135060 Extended by _Ray Chandler_, Nov 10 2009