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%I #11 Aug 16 2015 23:11:39
%S 0,1,2,3,4,5,6,7,8,9,12,13,16,17,18,19,20,21,22,23,24,25,28,29,32,33,
%T 48,49,64,65,66,67,68,69,70,71,72,73,76,77,80,81,82,83,84,85,86,87,88,
%U 89,92,93,96,97,112,113,128,129,132,133,144,145,148,149,192,193,196,197
%N Coprime sets of integers, each subset mapped onto a unique binary integer, values here shown in decimal.
%C A coprime set of integers has no pair of elements for which (i,j)=0. Each element i in a subset contributes 2^(i-1) to the binary value for that subset. The integers missing from the sequence correspond to non-coprime subsets.
%D Alan Sutcliffe, Divisors and Common Factors in Sets of Integers, awaiting publication.
%H Ivan Neretin, <a href="/A087087/b087087.txt">Table of n, a(n) for n = 0..3232 (all terms up to 2^20)</a>
%e a(11)=13 since the 11th coprime set counting from 0 is {4,3,1}, which maps onto 1101 binary = 13 decimal.
%t a = {}; Do[set = Select[Range[Log2[n] + 1], Reverse[IntegerDigits[n, 2]][[#]] == 1 &]; If[Union@Flatten@Outer[If[#1 == #2, 1, GCD[#1, #2]] &, set, set] == {1}, AppendTo[a, n]], {n, 200}]; a (* _Ivan Neretin_, Aug 14 2015 *)
%Y A087086 gives the corresponding values for the primitive sets of integers. A084422 gives the number of coprime subsets of the integers 1 to n.
%K easy,nonn,base
%O 0,3
%A Alan Sutcliffe (alansut(AT)ntlworld.com), Aug 16 2003
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