Tenemos la indeterminación de tipo
oo/oo,
tal que el límite para el numerador es
$$\lim_{x \to \infty} \left(x + 1\right)! = \infty$$
y el límite para el denominador es
$$\lim_{x \to \infty}\left(x + 1\right) = \infty$$
Vamos a probar las derivadas del numerador y denominador hasta eliminar la indeterminación.
$$\lim_{x \to \infty}\left(\frac{\left(x + 1\right)!}{x + 1}\right)$$
=
$$\lim_{x \to \infty}\left(\frac{\frac{d}{d x} \left(x + 1\right)!}{\frac{d}{d x} \left(x + 1\right)}\right)$$
=
$$\lim_{x \to \infty}\left(\Gamma\left(x + 2\right) \operatorname{polygamma}{\left(0,x + 2 \right)}\right)$$
=
$$\lim_{x \to \infty}\left(\frac{\frac{d}{d x} \Gamma\left(x + 2\right)}{\frac{d}{d x} \frac{1}{\operatorname{polygamma}{\left(0,x + 2 \right)}}}\right)$$
=
$$\lim_{x \to \infty}\left(- \frac{\Gamma\left(x + 2\right) \operatorname{polygamma}^{3}{\left(0,x + 2 \right)}}{\operatorname{polygamma}{\left(1,x + 2 \right)}}\right)$$
=
$$\lim_{x \to \infty}\left(\frac{\frac{d}{d x} \left(- \Gamma\left(x + 2\right) \operatorname{polygamma}^{3}{\left(0,x + 2 \right)}\right)}{\frac{d}{d x} \operatorname{polygamma}{\left(1,x + 2 \right)}}\right)$$
=
$$\lim_{x \to \infty}\left(\frac{- \Gamma\left(x + 2\right) \operatorname{polygamma}^{4}{\left(0,x + 2 \right)} - 3 \Gamma\left(x + 2\right) \operatorname{polygamma}^{2}{\left(0,x + 2 \right)} \operatorname{polygamma}{\left(1,x + 2 \right)}}{\operatorname{polygamma}{\left(2,x + 2 \right)}}\right)$$
=
$$\lim_{x \to \infty}\left(\frac{\frac{d}{d x} \frac{1}{\operatorname{polygamma}{\left(2,x + 2 \right)}}}{\frac{d}{d x} \frac{1}{- \Gamma\left(x + 2\right) \operatorname{polygamma}^{4}{\left(0,x + 2 \right)} - 3 \Gamma\left(x + 2\right) \operatorname{polygamma}^{2}{\left(0,x + 2 \right)} \operatorname{polygamma}{\left(1,x + 2 \right)}}}\right)$$
=
$$\lim_{x \to \infty}\left(- \frac{\left(- \Gamma\left(x + 2\right) \operatorname{polygamma}^{4}{\left(0,x + 2 \right)} - 3 \Gamma\left(x + 2\right) \operatorname{polygamma}^{2}{\left(0,x + 2 \right)} \operatorname{polygamma}{\left(1,x + 2 \right)}\right)^{2} \operatorname{polygamma}{\left(3,x + 2 \right)}}{\left(\Gamma\left(x + 2\right) \operatorname{polygamma}^{5}{\left(0,x + 2 \right)} + 7 \Gamma\left(x + 2\right) \operatorname{polygamma}^{3}{\left(0,x + 2 \right)} \operatorname{polygamma}{\left(1,x + 2 \right)} + 3 \Gamma\left(x + 2\right) \operatorname{polygamma}^{2}{\left(0,x + 2 \right)} \operatorname{polygamma}{\left(2,x + 2 \right)} + 6 \Gamma\left(x + 2\right) \operatorname{polygamma}{\left(0,x + 2 \right)} \operatorname{polygamma}^{2}{\left(1,x + 2 \right)}\right) \operatorname{polygamma}^{2}{\left(2,x + 2 \right)}}\right)$$
=
$$\lim_{x \to \infty}\left(\frac{\frac{d}{d x} \left(- \frac{\left(- \Gamma\left(x + 2\right) \operatorname{polygamma}^{4}{\left(0,x + 2 \right)} - 3 \Gamma\left(x + 2\right) \operatorname{polygamma}^{2}{\left(0,x + 2 \right)} \operatorname{polygamma}{\left(1,x + 2 \right)}\right)^{2} \operatorname{polygamma}{\left(3,x + 2 \right)}}{\operatorname{polygamma}^{2}{\left(2,x + 2 \right)}}\right)}{\frac{d}{d x} \left(\Gamma\left(x + 2\right) \operatorname{polygamma}^{5}{\left(0,x + 2 \right)} + 7 \Gamma\left(x + 2\right) \operatorname{polygamma}^{3}{\left(0,x + 2 \right)} \operatorname{polygamma}{\left(1,x + 2 \right)} + 3 \Gamma\left(x + 2\right) \operatorname{polygamma}^{2}{\left(0,x + 2 \right)} \operatorname{polygamma}{\left(2,x + 2 \right)} + 6 \Gamma\left(x + 2\right) \operatorname{polygamma}{\left(0,x + 2 \right)} \operatorname{polygamma}^{2}{\left(1,x + 2 \right)}\right)}\right)$$
=
$$\lim_{x \to \infty}\left(\frac{- \frac{2 \Gamma^{2}\left(x + 2\right) \operatorname{polygamma}^{9}{\left(0,x + 2 \right)} \operatorname{polygamma}{\left(3,x + 2 \right)}}{\operatorname{polygamma}^{2}{\left(2,x + 2 \right)}} - \frac{\Gamma^{2}\left(x + 2\right) \operatorname{polygamma}^{8}{\left(0,x + 2 \right)} \operatorname{polygamma}{\left(4,x + 2 \right)}}{\operatorname{polygamma}^{2}{\left(2,x + 2 \right)}} + \frac{2 \Gamma^{2}\left(x + 2\right) \operatorname{polygamma}^{8}{\left(0,x + 2 \right)} \operatorname{polygamma}^{2}{\left(3,x + 2 \right)}}{\operatorname{polygamma}^{3}{\left(2,x + 2 \right)}} - \frac{20 \Gamma^{2}\left(x + 2\right) \operatorname{polygamma}^{7}{\left(0,x + 2 \right)} \operatorname{polygamma}{\left(1,x + 2 \right)} \operatorname{polygamma}{\left(3,x + 2 \right)}}{\operatorname{polygamma}^{2}{\left(2,x + 2 \right)}} - \frac{6 \Gamma^{2}\left(x + 2\right) \operatorname{polygamma}^{6}{\left(0,x + 2 \right)} \operatorname{polygamma}{\left(1,x + 2 \right)} \operatorname{polygamma}{\left(4,x + 2 \right)}}{\operatorname{polygamma}^{2}{\left(2,x + 2 \right)}} + \frac{12 \Gamma^{2}\left(x + 2\right) \operatorname{polygamma}^{6}{\left(0,x + 2 \right)} \operatorname{polygamma}{\left(1,x + 2 \right)} \operatorname{polygamma}^{2}{\left(3,x + 2 \right)}}{\operatorname{polygamma}^{3}{\left(2,x + 2 \right)}} - \frac{6 \Gamma^{2}\left(x + 2\right) \operatorname{polygamma}^{6}{\left(0,x + 2 \right)} \operatorname{polygamma}{\left(3,x + 2 \right)}}{\operatorname{polygamma}{\left(2,x + 2 \right)}} - \frac{54 \Gamma^{2}\left(x + 2\right) \operatorname{polygamma}^{5}{\left(0,x + 2 \right)} \operatorname{polygamma}^{2}{\left(1,x + 2 \right)} \operatorname{polygamma}{\left(3,x + 2 \right)}}{\operatorname{polygamma}^{2}{\left(2,x + 2 \right)}} - \frac{9 \Gamma^{2}\left(x + 2\right) \operatorname{polygamma}^{4}{\left(0,x + 2 \right)} \operatorname{polygamma}^{2}{\left(1,x + 2 \right)} \operatorname{polygamma}{\left(4,x + 2 \right)}}{\operatorname{polygamma}^{2}{\left(2,x + 2 \right)}} + \frac{18 \Gamma^{2}\left(x + 2\right) \operatorname{polygamma}^{4}{\left(0,x + 2 \right)} \operatorname{polygamma}^{2}{\left(1,x + 2 \right)} \operatorname{polygamma}^{2}{\left(3,x + 2 \right)}}{\operatorname{polygamma}^{3}{\left(2,x + 2 \right)}} - \frac{18 \Gamma^{2}\left(x + 2\right) \operatorname{polygamma}^{4}{\left(0,x + 2 \right)} \operatorname{polygamma}{\left(1,x + 2 \right)} \operatorname{polygamma}{\left(3,x + 2 \right)}}{\operatorname{polygamma}{\left(2,x + 2 \right)}} - \frac{36 \Gamma^{2}\left(x + 2\right) \operatorname{polygamma}^{3}{\left(0,x + 2 \right)} \operatorname{polygamma}^{3}{\left(1,x + 2 \right)} \operatorname{polygamma}{\left(3,x + 2 \right)}}{\operatorname{polygamma}^{2}{\left(2,x + 2 \right)}}}{\Gamma\left(x + 2\right) \operatorname{polygamma}^{6}{\left(0,x + 2 \right)} + 12 \Gamma\left(x + 2\right) \operatorname{polygamma}^{4}{\left(0,x + 2 \right)} \operatorname{polygamma}{\left(1,x + 2 \right)} + 10 \Gamma\left(x + 2\right) \operatorname{polygamma}^{3}{\left(0,x + 2 \right)} \operatorname{polygamma}{\left(2,x + 2 \right)} + 27 \Gamma\left(x + 2\right) \operatorname{polygamma}^{2}{\left(0,x + 2 \right)} \operatorname{polygamma}^{2}{\left(1,x + 2 \right)} + 3 \Gamma\left(x + 2\right) \operatorname{polygamma}^{2}{\left(0,x + 2 \right)} \operatorname{polygamma}{\left(3,x + 2 \right)} + 18 \Gamma\left(x + 2\right) \operatorname{polygamma}{\left(0,x + 2 \right)} \operatorname{polygamma}{\left(1,x + 2 \right)} \operatorname{polygamma}{\left(2,x + 2 \right)} + 6 \Gamma\left(x + 2\right) \operatorname{polygamma}^{3}{\left(1,x + 2 \right)}}\right)$$
=
$$\lim_{x \to \infty}\left(\frac{- \frac{2 \Gamma^{2}\left(x + 2\right) \operatorname{polygamma}^{9}{\left(0,x + 2 \right)} \operatorname{polygamma}{\left(3,x + 2 \right)}}{\operatorname{polygamma}^{2}{\left(2,x + 2 \right)}} - \frac{\Gamma^{2}\left(x + 2\right) \operatorname{polygamma}^{8}{\left(0,x + 2 \right)} \operatorname{polygamma}{\left(4,x + 2 \right)}}{\operatorname{polygamma}^{2}{\left(2,x + 2 \right)}} + \frac{2 \Gamma^{2}\left(x + 2\right) \operatorname{polygamma}^{8}{\left(0,x + 2 \right)} \operatorname{polygamma}^{2}{\left(3,x + 2 \right)}}{\operatorname{polygamma}^{3}{\left(2,x + 2 \right)}} - \frac{20 \Gamma^{2}\left(x + 2\right) \operatorname{polygamma}^{7}{\left(0,x + 2 \right)} \operatorname{polygamma}{\left(1,x + 2 \right)} \operatorname{polygamma}{\left(3,x + 2 \right)}}{\operatorname{polygamma}^{2}{\left(2,x + 2 \right)}} - \frac{6 \Gamma^{2}\left(x + 2\right) \operatorname{polygamma}^{6}{\left(0,x + 2 \right)} \operatorname{polygamma}{\left(1,x + 2 \right)} \operatorname{polygamma}{\left(4,x + 2 \right)}}{\operatorname{polygamma}^{2}{\left(2,x + 2 \right)}} + \frac{12 \Gamma^{2}\left(x + 2\right) \operatorname{polygamma}^{6}{\left(0,x + 2 \right)} \operatorname{polygamma}{\left(1,x + 2 \right)} \operatorname{polygamma}^{2}{\left(3,x + 2 \right)}}{\operatorname{polygamma}^{3}{\left(2,x + 2 \right)}} - \frac{6 \Gamma^{2}\left(x + 2\right) \operatorname{polygamma}^{6}{\left(0,x + 2 \right)} \operatorname{polygamma}{\left(3,x + 2 \right)}}{\operatorname{polygamma}{\left(2,x + 2 \right)}} - \frac{54 \Gamma^{2}\left(x + 2\right) \operatorname{polygamma}^{5}{\left(0,x + 2 \right)} \operatorname{polygamma}^{2}{\left(1,x + 2 \right)} \operatorname{polygamma}{\left(3,x + 2 \right)}}{\operatorname{polygamma}^{2}{\left(2,x + 2 \right)}} - \frac{9 \Gamma^{2}\left(x + 2\right) \operatorname{polygamma}^{4}{\left(0,x + 2 \right)} \operatorname{polygamma}^{2}{\left(1,x + 2 \right)} \operatorname{polygamma}{\left(4,x + 2 \right)}}{\operatorname{polygamma}^{2}{\left(2,x + 2 \right)}} + \frac{18 \Gamma^{2}\left(x + 2\right) \operatorname{polygamma}^{4}{\left(0,x + 2 \right)} \operatorname{polygamma}^{2}{\left(1,x + 2 \right)} \operatorname{polygamma}^{2}{\left(3,x + 2 \right)}}{\operatorname{polygamma}^{3}{\left(2,x + 2 \right)}} - \frac{18 \Gamma^{2}\left(x + 2\right) \operatorname{polygamma}^{4}{\left(0,x + 2 \right)} \operatorname{polygamma}{\left(1,x + 2 \right)} \operatorname{polygamma}{\left(3,x + 2 \right)}}{\operatorname{polygamma}{\left(2,x + 2 \right)}} - \frac{36 \Gamma^{2}\left(x + 2\right) \operatorname{polygamma}^{3}{\left(0,x + 2 \right)} \operatorname{polygamma}^{3}{\left(1,x + 2 \right)} \operatorname{polygamma}{\left(3,x + 2 \right)}}{\operatorname{polygamma}^{2}{\left(2,x + 2 \right)}}}{\Gamma\left(x + 2\right) \operatorname{polygamma}^{6}{\left(0,x + 2 \right)} + 12 \Gamma\left(x + 2\right) \operatorname{polygamma}^{4}{\left(0,x + 2 \right)} \operatorname{polygamma}{\left(1,x + 2 \right)} + 10 \Gamma\left(x + 2\right) \operatorname{polygamma}^{3}{\left(0,x + 2 \right)} \operatorname{polygamma}{\left(2,x + 2 \right)} + 27 \Gamma\left(x + 2\right) \operatorname{polygamma}^{2}{\left(0,x + 2 \right)} \operatorname{polygamma}^{2}{\left(1,x + 2 \right)} + 3 \Gamma\left(x + 2\right) \operatorname{polygamma}^{2}{\left(0,x + 2 \right)} \operatorname{polygamma}{\left(3,x + 2 \right)} + 18 \Gamma\left(x + 2\right) \operatorname{polygamma}{\left(0,x + 2 \right)} \operatorname{polygamma}{\left(1,x + 2 \right)} \operatorname{polygamma}{\left(2,x + 2 \right)} + 6 \Gamma\left(x + 2\right) \operatorname{polygamma}^{3}{\left(1,x + 2 \right)}}\right)$$
=
$$\infty$$
Como puedes ver, hemos aplicado el método de l'Hopital (utilizando la derivada del numerador y denominador) 5 vez (veces)