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A117689 Cubes for which the product of the digits is a square. 1

%I #6 Aug 22 2021 13:31:33

%S 0,1,343,1000,1331,4096,8000,10648,19683,27000,39304,50653,64000,

%T 74088,79507,103823,110592,125000,140608,148877,205379,216000,238328,

%U 250047,300763,328509,343000,389017,405224,493039,512000,551368,592704,636056

%N Cubes for which the product of the digits is a square.

%C Any cube with a zero digit is a term of this sequence. Of the first 10,000 terms, only 331 have no zero digits. The largest such zero-free cube in the first 10,000 terms is 2956841564977. - _Harvey P. Dale_, Aug 22 2021

%H Harvey P. Dale, <a href="/A117689/b117689.txt">Table of n, a(n) for n = 0..10000</a>

%e 19683 is in the sequence because it is a cube and the product of its digits 1*9*6*8*3=1296 is a square.

%t Select[Range[0,100]^3,IntegerQ[Sqrt[Times@@IntegerDigits[#]]]&] (* _Harvey P. Dale_, Aug 22 2021 *)

%Y Cf. A000290, A000578.

%K nonn,base

%O 0,3

%A Luc Stevens (lms022(AT)yahoo.com), Apr 12 2006

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Last modified April 19 15:34 EDT 2024. Contains 371794 sequences. (Running on oeis4.)