%I
%S 1,1,1,3,1,3,5,1,5,7,1,7,9,1,9,11,1,11,13,1,13,15,1,15,17,1,17,19,1,
%T 19,21,1,21,23,1,23,25,1,25,27,1,27,29,1,29,31,1,31,33,1,33,35,1,35,
%U 37,1,37,39,1,39,41,1,41,43,1,43,45,1,45,47,1,47,49,1,49,51,1,51,53,1,53,55
%N Denominators of sequence of rationals defined by r(n) = n for n<=1 and for n>1: r(n) = (sum of denominators of r(n1) and r(n2))/(sum of numerators of r(n1) and r(n2)).
%C r(n) = A110090(n) / a(n);
%C a(n) = (A110090(n1)+A110090(n2)) / GCD(a(n1)+a(n2),A110090(n1)+A110090(n2)).
%F a(3*k) = 2*k+1, a(3*k+1) = 1, a(3*k+2) = 2*k+1.
%K nonn,frac
%O 0,4
%A _Reinhard Zumkeller_, Jul 14 2005
