nth term

[Emilijo]

If I know generating function of a series, what formula gives nth term?
Specifically, my generating function is f(x)=(Ʃ(k=1, to m-1) x^k)/(1-x^m)
***The function represent series: 0,1,1,...,1,0,1,1,...,1,0,...
where m is period; i.e. 0,1,1,0,1,1,0 m=3***

[Emilijo]

generating function is f(x)=(sum_(k=1,to m-1) x^k)/(1-x^m), where m is period;
0,1,1,0,1,1... m=3
0,1,1,1,0,1,1,1,0... m=4...

What is nth term of the series given by the generating function?
Formula must be general, so I can just put m.