\[ \boxed { x \left ( x-1 \right ) {\frac {{\rm d}^{2}}{{\rm d}{x}^{2}}}y \left ( x \right ) + \left ( \left ( a+1 \right ) x+b \right ) {\frac {\rm d}{{\rm d}x}}y \left ( x \right ) =0} \]
Mathematica: cpu = 0.045506 (sec), leaf count = 33 \[ \left \{\left \{y(x)\to \frac {c_1 x^{b+1} \, _2F_1(b+1,a+b+1;b+2;x)}{b+1}+c_2\right \}\right \} \]
Maple: cpu = 0.172 (sec), leaf count = 27 \[ \left \{ y \left ( x \right ) ={\it \_C1}+ {\mbox {$_2$F$_1$}(b+1,a+b+1;\,b+2;\,x)}{x}^{b+1}{\it \_C2} \right \} \]