A094872 phi(n)/tau(n), for odd squarefree n > 1 (A056911), phi = A000010, tau = A000005.

1, 2, 3, 5, 6, 2, 8, 9, 3, 11, 14, 15, 5, 6, 18, 6, 20, 21, 23, 8, 26, 10, 9, 29, 30, 12, 33, 11, 35, 36, 15, 39, 41, 16, 14, 44, 18, 15, 18, 48, 50, 51, 6, 53, 54, 18, 56, 22, 24, 20, 63, 21, 65, 27, 68, 69, 23, 30, 28, 74, 75, 30, 78, 26, 33, 81, 10, 83, 86, 29, 89, 90, 30, 36, 40

Offset: 1

Author

Lekraj Beedassy, Jun 16 2004

Keywords

• nonn

Links

• Ivan Neretin, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A056911.

Programs

Mathematica

EulerPhi[#]/DivisorSigma[0, #] & /@ Select[Range[3, 190, 2], SquareFreeQ] (* Ivan Neretin, Oct 04 2017 *)

PARI

for(n=1,95,if(issquarefree(k=2*n+1),print1(eulerphi(k)/numdiv(k),","))) \\ Klaus Brockhaus, Jun 16 2004

Formula

a(n) = A000010(A056911(n+1)) / A000005(A056911(n+1)). - Altug Alkan, Oct 04 2017

Extensions

Corrected and extended by Klaus Brockhaus, Jun 16 2004

a(16)=6 corrected by Ivan Neretin, Oct 04 2017