$\begin{array}{l}\phantom{\phantom{;}z\phantom{;}+4;}{\phantom{;}z^{2}-4z\phantom{;}+18\phantom{;}\phantom{;}}\\\phantom{;}z\phantom{;}+4\overline{\smash{)}\phantom{;}z^{3}\phantom{-;x^n}+2z\phantom{;}+1\phantom{;}\phantom{;}}\\\phantom{\phantom{;}z\phantom{;}+4;}\underline{-z^{3}-4z^{2}\phantom{-;x^n}\phantom{-;x^n}}\\\phantom{-z^{3}-4z^{2};}-4z^{2}+2z\phantom{;}+1\phantom{;}\phantom{;}\\\phantom{\phantom{;}z\phantom{;}+4-;x^n;}\underline{\phantom{;}4z^{2}+16z\phantom{;}\phantom{-;x^n}}\\\phantom{;\phantom{;}4z^{2}+16z\phantom{;}-;x^n;}\phantom{;}18z\phantom{;}+1\phantom{;}\phantom{;}\\\phantom{\phantom{;}z\phantom{;}+4-;x^n-;x^n;}\underline{-18z\phantom{;}-72\phantom{;}\phantom{;}}\\\phantom{;;-18z\phantom{;}-72\phantom{;}\phantom{;}-;x^n-;x^n;}-71\phantom{;}\phantom{;}\\\end{array}$

$z^{2}-4z+18+\frac{-71}{z+4}$