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This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A174894 Numbers such that the arithmetic mean of their distinct prime factors and the arithmetic mean of all of their prime factors are both integers.

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%I A174894 #12 Nov 16 2024 16:07:21
%S A174894 2,3,4,5,7,8,9,11,13,15,16,17,19,21,23,25,27,29,31,32,33,35,37,39,41,
%T A174894 42,43,47,49,51,53,55,57,59,61,64,65,67,69,71,73,77,78,79,81,83,85,87,
%U A174894 89,91,93,95,97,101
%N A174894 Numbers such that the arithmetic mean of their distinct prime factors and the arithmetic mean of all of their prime factors are both integers.
%C A174894 Subsequence of A078174 and A078175.
%C A174894 Complement of A176552. [From _Jaroslav Krizek_, Apr 21 2010]
%H A174894 Harvey P. Dale, <a href="/A174894/b174894.txt">Table of n, a(n) for n = 1..1000</a>
%e A174894 For a(11) = 16: 16 = 2^4; both (2+2+2+2)/4 and 2/1 are integers.
%t A174894 mdmaQ[n_]:=With[{fi=FactorInteger[n]},AllTrue[{Mean[Flatten[Table[#[[1]],#[[2]]]&/@fi]],Mean[fi[[;;,1]]]},IntegerQ]]; Select[Range[ 2,110],mdmaQ] (* _Harvey P. Dale_, Nov 16 2024 *)
%K A174894 nonn
%O A174894 1,1
%A A174894 _Jaroslav Krizek_, Apr 01 2010
%E A174894 Definition clarified by _Harvey P. Dale_, Nov 16 2024