plotting a piecewise function

Questions
,
1

I want to plot a function whose domain and range is N ( natural number ) with piecewise different condition for odd and even natural number. How can I do that??

2

This is not the role of the Piecewise function: it is more appropriate to simply use patterns in constructing your function. Here is an example:

f[n_Integer?EvenQ] := n 

f[n_Integer?OddQ] := (n^2)

and take a look at a ListPlot of a table of values

ListPlot[Table[f[i], {i, 0, 10}]]