%I A040080
%S A040080 9,2,18,2,18,2,18,2,18,2,18,2,18,2,18,2,18,2,18,2,18,2,
%T A040080 18,2,18,2,18,2,18,2,18,2,18,2,18,2,18,2,18,2,18,2,18,2,
%U A040080 18,2,18,2,18,2,18,2,18,2,18,2,18,2,18,2,18,2,18,2,18,2
%N A040080 Continued fraction for sqrt(90).
%H A040080 Harry J. Smith, <a href="b040080.txt">Table of n, a(n) for n=0,...,20000</
               a>
%H A040080 G. Xiao, <a href="http://wims.unice.fr/~wims/en_tool~number~contfrac.en.html">
               Contfrac</a>
%H A040080 <a href="Sindx_Con.html#confC">Index entries for continued fractions 
               for constants</a>
%F A040080 a(n)=10+8*(-1)^n]-9*[C(2*n,n) mod 2], with n>=0 [From Paolo P. Lava (ppl(AT)spl.at), 
               Jun 10 2009]
%e A040080 9.4868329805051379959966806... = 9 + 1/(2 + 1/(18 + 1/(2 + 1/(18 + ...)))) 
               [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), Jun 11 2009]
%p A040080 Digits := 100: convert(evalf(sqrt(N)),confrac,90,'cvgts'):
%o A040080 (PARI) { allocatemem(932245000); default(realprecision, 32000); x=contfrac(sqrt(90)); 
               for (n=0, 20000, write("b040080.txt", n, " ", x[n+1])); } [From Harry 
               J. Smith (hjsmithh(AT)sbcglobal.net), Jun 11 2009]
%Y A040080 Cf. A010541 Decimal expansion. [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), 
               Jun 11 2009]
%Y A040080 Sequence in context: A146492 A090298 A094581 this_sequence A098289 A152020 
               A055516
%Y A040080 Adjacent sequences: A040077 A040078 A040079 this_sequence A040081 A040082 
               A040083
%K A040080 nonn,cofr,easy
%O A040080 0,1
%A A040080 N. J. A. Sloane (njas(AT)research.att.com).