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!)
A300227 a(n) = number of steps in simple Euclidean algorithm for gcd(n,k) to reach the termination test n=k when starting with n = n and k = sigma(n)-1, with a(1) = 1. 6

%I #8 Mar 02 2018 22:44:22

%S 1,0,0,2,0,6,0,4,3,6,0,5,0,7,9,8,0,10,0,21,12,8,0,10,5,8,6,28,0,9,0,

%T 16,9,9,14,3,0,10,9,11,0,11,0,13,11,11,0,8,7,10,10,12,0,16,10,9,10,12,

%U 0,11,0,13,11,32,10,7,0,13,13,27,0,10,0,14,8,13,11,19,0,9,15,15,0,15,13,16,11,33,0,13,12,12,11,17,27,14,0

%N a(n) = number of steps in simple Euclidean algorithm for gcd(n,k) to reach the termination test n=k when starting with n = n and k = sigma(n)-1, with a(1) = 1.

%H Antti Karttunen, <a href="/A300227/b300227.txt">Table of n, a(n) for n = 1..65537</a>

%H Antti Karttunen, <a href="/A286594/a286594.txt">Scheme (Racket) program to compute this sequence</a>

%F a(1) = 1; for n > 1, a(n) = A285721(n,A000203(n)-1).

%o (PARI)

%o A285721(n,k) = if(n==k, 0, 1 + A285721(abs(n-k),min(n,k)));

%o A300227(n) = if(1==n,n,A285721(n,sigma(n)-1));

%Y Cf. A000203, A285721.

%Y Cf. also A286594, A300228, A300234, A300237, A300238.

%K nonn

%O 1,4

%A _Antti Karttunen_, Mar 02 2018

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 April 19 19:02 EDT 2024. Contains 371798 sequences. (Running on oeis4.)