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Index of the first occurrence of n in A085082. Smallest number having divisors with n distinct prime signatures.
1

%I #19 Jan 02 2021 04:50:54

%S 1,2,4,8,12,32,24,128,48,120,96,144,192,360,288,480,768,576,720,2592,

%T 1152,1728,2160,1440,3840,3456,4608,7200,2880,4320,15360,15120,10080,

%U 5760,20736,36864,8640,27648,11520,20160,50400,30240,25920,17280,82944

%N Index of the first occurrence of n in A085082. Smallest number having divisors with n distinct prime signatures.

%H Amiram Eldar, <a href="/A085083/b085083.txt">Table of n, a(n) for n = 1..10000</a>

%H <a href="/index/Pri#prime_signature">Index entries for sequences related to prime signature</a>

%e a(5) = 12 since the divisors of 12 are 1,2,3,4,6 and 12 and the five distinct prime signatures arising are 1, p, p*q, p^2 and p^2*q.

%Y Cf. A085082.

%Y Subsequence of A025487.

%K nonn

%O 1,2

%A _Amarnath Murthy_, Jul 01 2003

%E More terms from _David Wasserman_, Jan 25 2005