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%I #5 Sep 16 2015 13:35:07
%S 1,2,3,4,5,5,7,6,6,7,11,8,13,9,8,10,17,11,19,12,10,13,23,14,10,15,12,
%T 16,29,17,31,18,14,19,12,20,37,21,16,22,41,23,43,24,18,25,47,26,14,27,
%U 20,28,53,29,16,30,22,31,59,32,61,33,24,34,18,35,67,36,26,37,71,38,73,39
%N a(n)=the largest sum of two nontrivial divisors of n, if any, whose product equals n; otherwise, a(n)=n.
%C A divisor of n other than 1 or n is called nontrivial.
%e There are two ways to write 12 as a product of two nontrivial divisors, i.e., 6*2 and 4*3. Since 8=6+2>4+3=7, we have a(12)=8.
%t Table[If[Length[Divisors[n]] > 2, Max[Table[Divisors[n][[j]] + n/Divisors[n][[j]], {j, 2, Length[Divisors[n]] - 1}]], n], {n, 1, 100}] (* _Stefan Steinerberger_, Feb 04 2008 *)
%K nonn,easy
%O 1,2
%A _Joseph L. Pe_, Feb 01 2008
%E More terms from _Stefan Steinerberger_, Feb 04 2008
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