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A187104 Numbers n with property that the largest proper divisor of n is a cube. 3

%I #16 Aug 09 2014 23:00:04

%S 16,54,81,128,250,375,432,625,686,1024,1029,1458,1715,2000,2187,2401,

%T 2662,3456,3993,4394,5488,6591,6655,6750,8192,9317,9826,10125,10985,

%U 11664,13718,14641,14739,15379,16000,18522,20577,21296,24167,24334

%N Numbers n with property that the largest proper divisor of n is a cube.

%C Corresponding cubes are: 8, 27, 27, 64, 125, 125, 216, 125, 343, 512, 343, 729, 343, 1000, 729, 343, 1331, 1728, 1331, 2197, 2744, 2197, 1331, 3375, 4096, 1331, 4913, 3375, 2197, 5832, 6859, 1331, 4913, 2197, 8000.

%H Zak Seidov, <a href="/A187104/b187104.txt">Table of n, a(n) for n = 1..2671, a(n) up to 10^9</a>

%t Select[Range[54000], MoebiusMu[#] == 0 && IntegerQ[Divisors[#][[-2]]^(1/3)] &] (* _Alonso del Arte_, Mar 04 2011 *)

%o (PARI) lista(nn) = {forcomposite(n=1, nn, if (ispower(divisors(n)[numdiv(n)-1], 3), print1(n, ", ")););} \\ _Michel Marcus_, Aug 09 2014

%Y Cf. A187101 (largest proper divisor is a square).

%K nonn

%O 1,1

%A _Zak Seidov_, Mar 04 2011

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Last modified April 23 18:16 EDT 2024. Contains 371916 sequences. (Running on oeis4.)