\[ \boxed { 2\,x \left ( x-1 \right ) {\frac {{\rm d}^{2}}{{\rm d}{x}^{2}}}y \left ( x \right ) + \left ( 2\,x-1 \right ) {\frac {\rm d}{{\rm d}x}}y \left ( x \right ) + \left ( ax+b \right ) y \left ( x \right ) =0} \]
Mathematica: cpu = 1.377675 (sec), leaf count = 55 \[ \left \{\left \{y(x)\to \text {DifferentialRoot}\left (\{\unicode {f818},\unicode {f817}\}\unicode {f4a1}\left \{(\unicode {f817} a+b) \unicode {f818}(\unicode {f817})+(2 \unicode {f817}-1) \unicode {f818}'(\unicode {f817})+2 (\unicode {f817}-1) \unicode {f817} \unicode {f818}''(\unicode {f817})=0,\unicode {f818}(2)=c_1,\unicode {f818}'(2)=c_2\right \}\right )(x)\right \}\right \} \]
Maple: cpu = 0.078 (sec), leaf count = 39 \[ \left \{ y \left ( x \right ) ={\it \_C1}\,{\it MathieuC} \left ( -a-2\,b ,{\frac {a}{2}},\arccos \left ( \sqrt {x} \right ) \right ) +{\it \_C2} \,{\it MathieuS} \left ( -a-2\,b,{\frac {a}{2}},\arccos \left ( \sqrt {x } \right ) \right ) \right \} \]