I tried to search on the internet, to read my course multiple times, but the only thing I see are definitions of the primitive polynomials for an LFSR.
I have an exercise: Find the primitive polynomial of the LFSR of width 4 with longest possible period.
And I just don't know where to begin from.
By all I read, I know that it is irreducible and that the period will be $2^4-1$, so 15.
How do I find it?