This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A249783 Smallest index of a Fibonacci-like sequence containing n, see comments. 5
 0, 1, 1, 1, 2, 1, 2, 3, 1, 3, 2, 3, 4, 1, 4, 3, 2, 5, 3, 5, 4, 1, 6, 4, 3, 5, 2, 7, 5, 3, 6, 5, 4, 6, 1, 7, 6, 4, 7, 3, 5, 7, 2, 8, 7, 5, 8, 3, 6, 8, 5, 9, 4, 6, 9, 1, 7, 9, 6, 10, 4, 7, 10, 3, 8, 5, 7, 11, 2, 8, 11, 7, 9, 5, 8, 12, 3, 9, 6, 8, 10, 5, 9, 13, 4, 10, 6, 9, 11, 1, 10, 7, 9, 11, 6, 10, 12, 4, 11, 7, 10 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,5 COMMENTS Any two nonnegative integers F0 and F1 generate a Fibonacci-like sequence where for n > 1, Fn = F[n-1] + F[n-2]. Call F0 + F1 the "index" of such a sequence. In this sequence, a(n) is the smallest occurring index of any Fibonacci-like sequence containing n. LINKS Charles R Greathouse IV, Table of n, a(n) for n = 0..10000 FORMULA a(n) <= A054495(n) <= n. - Charles R Greathouse IV, Nov 06 2014 EXAMPLE For n = 0, the trivial sequence 0, 0, 0, ... has index 0. For n = 5, the classic Fibonacci sequence 0, 1, 1, 2, 3, 5, ... contains 5 and has index 1. For n = 7, the Lucas sequence 2, 1, 3, 4, 7, ... contains 7, and no such sequence with a smaller index contains 7. MATHEMATICA a[n_] := Module[{a, k, A, B}, If[n<2, Return[n]]; For[k=1, k <= n-1, k++, For[a=0, a <= k-1, a++, A=a; B=k-A; While[B 0 is an element of A000045, a(n) = 1. If n > 2 is twice such an element, a(n) = 2. If n > 3 is an element of A000032 or of A022086, a(n) = 3. Sequence in context: A082076 A231516 A048793 * A209278 A286343 A075106 Adjacent sequences:  A249780 A249781 A249782 * A249784 A249785 A249786 KEYWORD nonn,look,nice AUTHOR Allan C. Wechsler, Nov 05 2014 EXTENSIONS Extended by Charles R Greathouse IV, Nov 06 2014 STATUS approved

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

Last modified May 21 15:32 EDT 2019. Contains 323444 sequences. (Running on oeis4.)