A300228 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 = 1+phi(n).

1, 0, 0, 3, 0, 1, 0, 4, 5, 1, 0, 5, 0, 1, 3, 6, 0, 6, 0, 7, 6, 1, 0, 4, 9, 1, 7, 9, 0, 5, 0, 10, 5, 1, 4, 8, 0, 1, 8, 9, 0, 9, 0, 13, 5, 1, 0, 9, 13, 8, 7, 15, 0, 10, 16, 11, 10, 1, 0, 12, 0, 1, 9, 18, 19, 9, 0, 19, 9, 6, 0, 12, 0, 1, 12, 21, 11, 13, 0, 10, 13, 1, 0, 10, 7, 1, 11, 13, 0, 6, 22, 25, 14, 1, 13, 12, 0, 10, 12, 10, 0, 13, 0, 15, 8

Offset: 1

Author

Antti Karttunen, Mar 02 2018

Keywords

• nonn

Links

• Antti Karttunen, Table of n, a(n) for n = 1..65537
• Antti Karttunen, Scheme (Racket) program to compute this sequence

Crossrefs

Cf. A000010, A285721.

Cf. also A286594, A300227, A300234, A300237, A300238.

Programs

PARI

A285721(n,k) = if(n==k, 0, 1 + A285721(abs(n-k),min(n,k)));
A300228(n) = A285721(n,1+eulerphi(n));

Formula

a(n) = A285721(n,1+A000010(n)).