Xn+1 = k(Xn)(1-Xn)

The left hand equation is a cobweb plot. The parabola

y = k(x)(1-x)

is shown and the positive diagonal.

The cobweb plots Xn versus Xn-1 with stops along stops on the positive diagonal.

The right hand is an interation plot. You can adjust k and the first value in the interation (technically Xo).