x^4 - x^3 + 5*x^2 + 4*x + 16
x^4 - x^3 - 6*x^2 + x + 1
x^4 - x^3 - 4*x + 1
x^4 - x^3 + 6*x^2 - 5*x + 8
x^4 - x^3 + 11*x^2 + x + 52
x^4 - x^3 - 2*x - 13