%I A087081
%S A087081 0,1,6,24,48,156,192,580,836,1444,1660,4596,4980,13184,14768,17308,
%T A087081 21756,55888,58768,146416,157552,181008,196304,481664,500096,765648,
%U A087081 825152,1073920,1148288,2745728,2768768,6505728,7453952,8233792,8736960
%N A087081 Sum of the elements in the coprime subsets of the integers 1 to n.
%C A087081 A coprime set of integers has (m,n)=1 for each pair of integers in the 
               set.
%D A087081 Alan Sutcliffe, Divisors and Common Factors in Sets of Integers, awaiting 
               publication.
%e A087081 a(4)=48 since the 12 coprime subsets of (1,2,3,4) are ( ) (1) (2) (3) 
               (4) (1,2) (1,3) (1,4) (2,3) (3,4) (1,2,3) (1,3 4) and the sum of 
               the elements is 48.
%Y A087081 A087078 gives the sum of the elements in the primitive subsets. A084422 
               gives the number coprime subsets. A087080 gives the number of elements 
               in coprime subsets.
%Y A087081 Sequence in context: A120572 A000056 A083170 this_sequence A089973 A033581 
               A009943
%Y A087081 Adjacent sequences: A087078 A087079 A087080 this_sequence A087082 A087083 
               A087084
%K A087081 nonn
%O A087081 0,3
%A A087081 Alan Sutcliffe (alansut(AT)ntlworld.com), Aug 12 2003