Generating dataset for LFSR stream cipher
Firstly using an LFSR output as a keystream generator is insecure, due to the Berlekamp-Massey attack which only needs $2m$ bits of known or guessed plaintext to break the stream with period $2^m-1.$

The coefficients  you are asking about, must define a polynomial $$c(x)=c_0+c_1 x +c_{m-1} x^{m-1}+x^m$$ with $c_0=1,$ and $c(x)$ must be primitive. See Wikipedia here.