%I A081785
%S A081785 0,1,5,55,14187,314681540,254841004490568887,
%T A081785 116515298784769863036311841843812470,
%U A081785 16752745298264669840183664790312981823804061660537952218518280274360024
%N A081785 Continued cotangent for log(2).
%F A081785 log(2)=cot(sum(n>=0, n, (-1)^n*acot(a(n))); let b(0)=log(2), b(n)=(b(n-1)*floor(b(n-1))+1)/
               (b(n-1)-floor(b(n-1)) then a(n)=floor(b(n))
%o A081785 (PARI) ?bn=vector(100); b(n)=if(n<0,0,bn[n]); bn[1]=log(2); ?for(n=2,
               10,bn[n]=(b(n-1)*floor(b(n-1))+1)/(b(n-1)-floor(b(n-1)))) ?a(n)=floor(b(n+1))
%Y A081785 Cf. A001620, A002666, A002667.
%Y A081785 Sequence in context: A068666 A082780 A063855 this_sequence A144996 A129440 
               A045729
%Y A081785 Adjacent sequences: A081782 A081783 A081784 this_sequence A081786 A081787 
               A081788
%K A081785 nonn
%O A081785 0,3
%A A081785 Benoit Cloitre (benoit7848c(AT)orange.fr), Apr 10 2003