Create repeated pole/zero in transfer function---Octave
You can create the transfer function

$$H(s) = \frac{s^2}{s+2}$$

Using the Matlab command

H = tf([1, 0, 0], [1, 2])

If you ever want to find the polynomial coefficients of a multiplication, for example to find the expanded form of a repeated non-zero root, you can use the function

expanded = conv([1, 1], [1, 1])

Which will compute

$$(s+1)\cdot (s+1) = (s+1)^2 = s^2 + 2s + 1$$

Hence it will return

[1, 2, 1]

Hope this helps!