The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A057431 Obtained by reading first the numerator then the denominator of fractions in full Stern-Brocot tree (A007305/A047679). 3
 0, 1, 1, 0, 1, 1, 1, 2, 2, 1, 1, 3, 2, 3, 3, 2, 3, 1, 1, 4, 2, 5, 3, 5, 3, 4, 4, 3, 5, 3, 5, 2, 4, 1, 1, 5, 2, 7, 3, 8, 3, 7, 4, 7, 5, 8, 5, 7, 4, 5, 5, 4, 7, 5, 8, 5, 7, 4, 7, 3, 8, 3, 7, 2, 5, 1, 1, 6, 2, 9, 3, 11, 3, 10, 4, 11, 5, 13, 5, 12, 4, 9, 5, 9, 7, 12, 8, 13, 7, 11, 7, 10, 8, 11, 7, 9, 5, 6, 6, 5 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,8 COMMENTS When presented in this way, every row (e.g. row 3, 1 3 2 3 3 2 3 1) is a palindrome. - Joshua Zucker, May 11 2006 LINKS Alois P. Heinz, Table of n, a(n) for n = 0..10000 N. J. A. Sloane, Stern-Brocot or Farey Tree Index entries for sequences related to Stern's sequences MAPLE F:= proc(n) option remember; local t; t:= L -> [[L[1], [L[1][1]+L[2][1], L[1][2]+L[2][2]], L[2]], [L[2], [L[2][1]+L[3][1], L[2][2]+L[3][2]], L[3]]][]; if n=0 then [[[ ], [0, 1], [ ]], [[ ], [1, 0], [ ]]] elif n=1 then [[[0, 1], [1, 1], [1, 0]]] else map(t, F(n-1)) fi end: aa:= n-> map(x-> x[], [seq(map(x-> x[2], F(j))[], j=0..n)])[]: aa(7); # aa(n) gives the first 2^(n+1)+2 terms # Alois P. Heinz, Jan 13 2011 MATHEMATICA sbt[n_] := Module[{R, L, Y, w, u}, R = {{1, 0}, {1, 1}}; L = {{1, 1}, {0, 1}}; Y = {{1, 0}, {0, 1}}; w[b_] := Fold[#1.If[#2 == 0, L, R]&, Y, b]; u[a_] := {a[[2, 1]] + a[[2, 2]], a[[1, 1]] + a[[1, 2]]}; Map[u, Map[w, Tuples[{0, 1}, n]]]]; Join[{0, 1, 1, 0}, Table[sbt[n], {n, 0, 5}]] // Flatten (* Jean-François Alcover, Sep 06 2022, after Peter Luschny in A007305 *) CROSSREFS Cf. A007305, A047679, A007306, A002487, A057432. Sequence in context: A288533 A093869 A329870 * A179541 A057060 A198380 Adjacent sequences: A057428 A057429 A057430 * A057432 A057433 A057434 KEYWORD nonn,look,easy AUTHOR N. J. A. Sloane, Sep 08 2000 EXTENSIONS More terms from Joshua Zucker, May 11 2006 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified June 15 02:53 EDT 2024. Contains 373402 sequences. (Running on oeis4.)