Search: id:A081780
Results 1-1 of 1 results found.

%I A081780
%S A081780 1,3,16,405,672320,1352290629546,4817801789405093582066881,
%T A081780 125242334906904794515426191021121381708761081802849,
%U A081780 48098205042808280233282792304806428848378744166690329294696649253234314988369597043479633480454760546
%N A081780 Continued cotangent for square root of 3.
%F A081780 sqrt(3)=cot(sum(n>=0, n, (-1)^n*acot(a(n))); let b(0)=sqrt(3), b(n)=(b(n-1)*floor(b(n-1))+1)/
               (b(n-1)-floor(b(n-1)) then a(n)=floor(b(n))
%o A081780 (PARI) ?bn=vector(100); b(n)=if(n<0,0,bn[n]); bn[1]=sqrt(3); ?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 A081780 Cf. A002666, A002667.
%Y A081780 Sequence in context: A005031 A054939 A081782 this_sequence A002794 A132559 
               A080273
%Y A081780 Adjacent sequences: A081777 A081778 A081779 this_sequence A081781 A081782 
               A081783
%K A081780 nonn
%O A081780 0,2
%A A081780 Benoit Cloitre (benoit7848c(AT)orange.fr), Apr 10 2003

Search completed in 0.001 seconds