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.
%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