A259439 - OEIS

%I #58 Oct 21 2015 05:58:26

%S 1,1,1,1,1,2,1,2,3,5,3,6,3,4,3,4,3,6,3,5,5,7,5,12,5,11,9,14,7,23,7,13,

%T 11,16,13,24,11,22,17,25,11,36,13,29,25,29,17,47,19,40,27,37,19,53,25,

%U 43,29,37,19,67,19,37,31,37,25,61,23,47,37,67,29,83

%N a(n) = A143482(n)/n.

%C a(1) = 1. For n > 1, a(n) is the least positive k such that phi(k*n) >= phi(a(n-1)*(n-1)), where phi(m) is A000010(m).

%H Peter Kagey, <a href="/A259439/b259439.txt">Table of n, a(n) for n = 1..10000</a>

%t a = t = {1}; lim = 72; Do[k = 1; While[EulerPhi[k n] < t[[n - 1]], k++]; AppendTo[a, k]; AppendTo[t, EulerPhi[k n]], {n, 2, lim}]; a (* _Michael De Vlieger_, Sep 22 2015 *)

%o (PARI) lista(nn) = {print1(a=1, ", "); for (n=2, nn, k = 1; phia = eulerphi(a); while(eulerphi(k*n) < phia, k++); a = k*n; print1(k, ", "););} \\ _Michel Marcus_, Oct 05 2015

%Y Cf. A143482.

%K nonn

%O 1,6

%A _Peter Kagey_, Sep 03 2015