[x^4 - x^3 - 3*x^2 - x + 1, \
 x^4 - x^3 - 3*x^2 - 7*x + 1, \
 x^4 + x^3 - x^2 + 2*x + 4, \
 x^4 + x^3 - 2*x + 1]