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%I #16 Aug 21 2019 05:40:17
%S 6,30,36,60,120,180,210,216,240,420,480,840,900,960,1080,1260,1296,
%T 1680,1800,1920,2310,2520,3360,3600,3840,4620,5040,5400,6300,6480,
%U 6720,7200,7560,7680,7776,9240,10080,12600,13440,13860,14400,15120,15360,18480
%N Numbers with decreasing but not strictly decreasing prime signature.
%C All numbers of the form 2^k1*3^k2*...*p_n^k_n, where k1 >= k2 >= ... >= k_n, and the '=' occurs at least once, sorted.
%C It appears that all highly composite numbers (A002182) greater than 720 are in this sequence. - _Walter Roscello_, Dec 24 2013
%H Amiram Eldar, <a href="/A161812/b161812.txt">Table of n, a(n) for n = 1..10000</a> (terms 1..279 from Walter Roscello)
%e a(1) = 2*3, a(2) = 2*3*5, a(3) = 2^2*3^2, a(4) = 2^2*3*5.
%t okQ[n_] := Module[{pp, ee}, {pp, ee} = Transpose[FactorInteger[n]]; Length[pp] == PrimePi[pp // Last] && GreaterEqual @@ ee && Sort[ee] != Union[ee]]; Select[Range[20000], okQ] (* _Jean-François Alcover_, Jun 17 2019 *)
%Y Cf. A025487, A087980, A002182.
%K easy,nonn
%O 1,1
%A _Peter Luschny_, Jun 20 2009
%E Terms up to n=279 added by _Walter Roscello_, Dec 24 2013
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