Search: id:A020650 Results 1-1 of 1 results found. %I A020650 %S A020650 1,2,1,3,1,3,2,4,1,4,3,5,2,5,3,5,1,5,4,7,3,7,4,7,2,7,5,8,3,8,5,6,1,6,5, 9, %T A020650 4,9,5,10,3,10,7,11,4,11,7,9,2,9,7,12,5,12,7,11,3,11,8,13,5,13,8,7,1,7, 6, %U A020650 11,5,11,6,13,4,13,9,14,5,14,9,13,3,13,10,17,7,17,10,15,4,15,11,18,7,18 %N A020650 Numerators in recursive bijection from positive integers to positive rationals (the bijection is f(1) = 1, f(2n) = f(n)+1, f(2n+1) = 1/ (f(n)+1)). %C A020650 The fractions are given in their reduced form, thus gcd(a(n), A020651(n)) = 1 for all n. - Antti Karttunen (Antti.Karttunen(AT)iki.fi), May 26 2004 %H A020650 T. D. Noe, Table of n, a(n) for n=1..10000 %F A020650 a(1) = 1, a(2n) = a(n)+A020651(n), a(2n+1) = A020651(2n) = A020651(n) - Antti Karttunen (Antti.Karttunen(AT)iki.fi), May 26 2004 %e A020650 1, 2, 1/2, 3, 1/3, 3/2, 2/3, 4, 1/4, 4/3, ... %p A020650 A020650 := n -> `if`((n < 2),n, `if`(type(n,even), A020650(n/2)+A020651(n/ 2), A020651(n-1))); %Y A020650 Cf. A020651. %Y A020650 Bisection: A086592. %Y A020650 Sequence in context: A144079 A071575 A038569 this_sequence A124224 A014599 A075825 %Y A020650 Adjacent sequences: A020647 A020648 A020649 this_sequence A020651 A020652 A020653 %K A020650 nonn,easy,frac,nice %O A020650 1,2 %A A020650 David W. Wilson (davidwwilson(AT)comcast.net) Search completed in 0.001 seconds