login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A120839 a(n) is the n-th positive integer which is coprime to the n-th Fibonacci number. 2

%I #17 Dec 27 2019 07:46:39

%S 1,2,5,5,6,11,7,13,19,13,11,35,13,15,37,26,17,39,19,43,45,22,23,85,31,

%T 26,59,46,29,87,31,58,65,34,47,125,37,39,77,101,41,95,43,67,121,46,47,

%U 179,53,68,101,77,53,125,68,109,119,58,59,263,61,62,145,115,81,133,67

%N a(n) is the n-th positive integer which is coprime to the n-th Fibonacci number.

%H Michael De Vlieger, <a href="/A120839/b120839.txt">Table of n, a(n) for n = 1..5000</a>

%e 55 is the 10th Fibonacci number. 1,2,3,4,6,7,8,9,12,13,14,16,... is the sequence of positive integers which are coprime to 55. 13 is the 10th of these integers, so a(10)=13.

%t Table[Block[{m = Fibonacci@ n, r = {1}, k = 2}, While[Length@ r < n, If[GCD[k, m] == 1, AppendTo[r, k], Nothing]; k++]; Last@ r], {n, 67}] // Flatten (* _Michael De Vlieger_, Dec 26 2019 *)

%Y Diagonal of A129322.

%K nonn

%O 1,2

%A _Leroy Quet_, Aug 18 2006

%E Extended by _Ray Chandler_, Aug 22 2006

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.

License Agreements, Terms of Use, Privacy Policy. .

Last modified September 15 22:03 EDT 2024. Contains 375955 sequences. (Running on oeis4.)