login
a(n) = m-th positive integer which is coprime to n, where phi(n) is number of positive integers which are <= n and are coprime to n and m = phi(n) if phi(n)|n, else m = n mod phi(n)..
2

%I #10 Oct 11 2019 14:02:56

%S 1,1,1,3,1,5,1,7,4,3,1,11,1,3,13,15,1,17,1,9,16,3,1,23,6,3,13,9,1,19,

%T 1,31,20,3,16,35,1,3,23,19,1,19,1,7,38,3,1,47,8,23,29,7,1,53,19,17,32,

%U 3,1,43,1,3,46,63,22,19,1,7,38,61,1,71,1,3,64,7,20,19,1,39,40,3,1,41,27,3

%N a(n) = m-th positive integer which is coprime to n, where phi(n) is number of positive integers which are <= n and are coprime to n and m = phi(n) if phi(n)|n, else m = n mod phi(n)..

%t f[n_] := Block[{k = 0, m = Mod[n, EulerPhi[n], 1]},While[m > 0,k++;While[GCD[n, k] > 1, k++ ];m--;];k];Table[f[n], {n, 90}] (* _Ray Chandler_, Oct 26 2006 *)

%Y Cf. A000010, A122377, A124333.

%K nonn

%O 1,4

%A _Leroy Quet_, Oct 19 2006

%E Edited and extended by _Ray Chandler_, Oct 26 2006