%I A093875
%S A093875 1,2,2,3,3,3,3,4,4,5,5,4,4,5,5,5,5,7,7,7,7,8,8,5,5,7,7,7,7,8,8,6,6,9,9,
%T A093875 10,10,11,11,9,9,12,12,11,11,13,13,6,6,9,9,10,10,11,11,9,9,12,12,11,11,
%U A093875 13,13,7,7,11,11,13,13,14,14,13,13,17,17,15,15,18,18,11,11,16,16
%N A093875 Denominators in Kepler's tree of harmonic fractions.
%C A093875 Form a tree of fractions by beginning with 1/1 and then giving every 
               node i/j two descendants labeled i/(i+j) and j/(i+j).
%H A093875 R. Zumkeller, <a href="b093875.txt">Table of n, a(n) for n = 1..10000</
               a>
%F A093875 a(n) = a([n/2]) + A093873([n/2]).
%e A093875 The first few fractions are:
%e A093875 1 1 1 1 2 1 2 1 3 2 3 1 3 2 3 1 4 3 4 2 5 3 5 1 4 3 4 2 5 3 5
%e A093875 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ...
%e A093875 1 2 2 3 3 3 3 4 4 5 5 4 4 5 5 5 5 7 7 7 7 8 8 5 5 7 7 7 7 8 8
%Y A093875 The numerators are in A093875. Usually one only considers the left-hand 
               half of the tree, which gives the fractions A020651/A086592. See 
               A086592 for more information, references to Kepler, etc.
%Y A093875 Sequence in context: A101402 A156251 A116458 this_sequence A114214 A074198 
               A048688
%Y A093875 Adjacent sequences: A093872 A093873 A093874 this_sequence A093876 A093877 
               A093878
%K A093875 nonn,easy,frac
%O A093875 1,2
%A A093875 N. J. A. Sloane (njas(AT)research.att.com) and Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), 
               May 24 2004