/ 2 \
\polygamma (0, 1 + n) + polygamma(1, 1 + n)/*gamma(1 + n)
$$\left(\operatorname{polygamma}^{2}{\left (0,n + 1 \right )} + \operatorname{polygamma}{\left (1,n + 1 \right )}\right) \Gamma{\left(n + 1 \right)}$$
/ 3 \
\polygamma (0, 1 + n) + 3*polygamma(0, 1 + n)*polygamma(1, 1 + n) + polygamma(2, 1 + n)/*gamma(1 + n)
$$\left(\operatorname{polygamma}^{3}{\left (0,n + 1 \right )} + 3 \operatorname{polygamma}{\left (0,n + 1 \right )} \operatorname{polygamma}{\left (1,n + 1 \right )} + \operatorname{polygamma}{\left (2,n + 1 \right )}\right) \Gamma{\left(n + 1 \right)}$$