Farey(n)=my(v=List()); for(k=1,n,for(i=0,k,listput(v,i/k))); vecsort(Set(v));
countFarey(n)=1+sum(k=1, n, eulerphi(k));
fmt(n)=if(denominator(n)>1,n,Str(n,"/1"));
for(n=1,11,print(apply(fmt, Farey(n))))
apply(countFarey, 100*[1..10])