OFFSET
1,2
LINKS
Ivan Neretin, Table of n, a(n) for n = 1..10000
FORMULA
MATHEMATICA
EulerPhi[#]/DivisorSigma[0, #] & /@ Select[Range[3, 190, 2], SquareFreeQ] (* Ivan Neretin, Oct 04 2017 *)
PROG
(PARI) for(n=1, 95, if(issquarefree(k=2*n+1), print1(eulerphi(k)/numdiv(k), ", "))) \\ Klaus Brockhaus, Jun 16 2004
CROSSREFS
KEYWORD
nonn
AUTHOR
Lekraj Beedassy, Jun 16 2004
EXTENSIONS
Corrected and extended by Klaus Brockhaus, Jun 16 2004
a(16)=6 corrected by Ivan Neretin, Oct 04 2017
STATUS
approved