Search: id:A006466 Results 1-1 of 1 results found. %I A006466 M0049 %S A006466 1,1,1,1,2,1,1,1,1,1,1,1,2,1,1,1,1,2,1,1,1,1,2,1,2,1,1,1,1,2,1,1,1,1,1, %T A006466 1,1,2,1,1,1,1,2,1,2,1,1,1,1,1,1,1,2,1,1,1,1,2,1,2,1,1,1,1,2,1,1,1,1,2, %U A006466 1,1,1,1,1,1,1,2,1,1,1,1,2,1,2,1,1,1,1,1,1,1,2,1,1,1,1,2,1,1,1,1,2,1,2 %N A006466 Continued fraction expansion of C = 2*sum( 1/2^(2^n), n=0 to infinity ). %C A006466 C arises when looking for a sequence b(n) such that : b(1)=0, b(n+1) is the smallest integer > b(n) such that the continued fraction for 1/2^b(1)+1/2^b(2)+...+1/2^b(n+1) contains only 1's or 2's. Because b(n)=2^n-1 and C = sum(k>=0,1/2^b(k)). - Benoit Cloitre (benoit7848c(AT)orange.fr), Nov 03 2002 %D A006466 J. O. Shallit, Simple continued fractions for some irrational numbers. J. Number Theory 11 (1979), no. 2, 209-217. %D A006466 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %H A006466 Harry J. Smith, Table of n, a(n) for n=0,...,20000 %H A006466 J. O. Shallit, Simple continued fractions for some irrational numbers. J. Number Theory 11 (1979), no. 2, 209-217. %F A006466 Recurrence: a(5n)=a(5n+1)=a(2)=a(5n+3)=a(20n+14)=a(40n+9)=1, a(20n+4)=a(40n+29)=2, a(5n+2)=3-a(5n-1), a(20n+19)=a(10n+9). - Ralf Stephan (ralf(AT)ark.in-berlin.de), May 17 2005 %e A006466 1.632843018043786287416159475... = 1 + 1/(1 + 1/(1 + 1/(1 + 1/(2 + ...)))) [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), May 09 2009] %o A006466 (PARI) { allocatemem(932245000); default(realprecision, 10000); x=suminf(n=0, 1/2^(2^n)); x=contfrac(2*x); for (n=1, 20001, write("b006466.txt", n-1, " ", x[n])); } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), May 09 2009] %Y A006466 Cf. A076214 = Decimal expansion. [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), May 09 2009] %Y A006466 Sequence in context: A072911 A053150 A163379 this_sequence A086597 A031214 A056059 %Y A006466 Adjacent sequences: A006463 A006464 A006465 this_sequence A006467 A006468 A006469 %K A006466 nonn,cofr %O A006466 0,5 %A A006466 N. J. A. Sloane (njas(AT)research.att.com). %E A006466 Better description and more terms from Antonio G. Astudillo (afg_astudillo(AT)hotmail.com), Jun 19 2001 Search completed in 0.001 seconds