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A023886 Average of proper divisors (excluding 1) is an integer. 6

%I

%S 4,8,9,15,18,21,25,27,33,35,39,45,49,51,55,57,63,65,69,75,77,81,85,87,

%T 91,93,95,98,99,111,115,117,119,121,123,125,128,129,133,141,143,145,

%U 147,153,155,159,161,162,169,171,175,177,183,185,187,201,203

%N Average of proper divisors (excluding 1) is an integer.

%H Vincenzo Librandi, <a href="/A023886/b023886.txt">Table of n, a(n) for n = 1..1000</a>

%t Select[Range[210],IntegerQ[Mean[Rest[Most[Divisors[#]]]]]&] (* _Harvey P. Dale_, Feb 20 2011 *)

%K nonn

%O 1,1

%A _Olivier GĂ©rard_

%E Clarified definition -- Harvey P. Dale, Feb 20 2011

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Last modified May 26 19:26 EDT 2019. Contains 323597 sequences. (Running on oeis4.)