Planck law for a different distribution

Question

I try to obtain <E> from following formula. But How can I do the summation?

$\frac{\sum _{n=0}^{\infty }\left(n\:h\upsilon \left(1+\left(1-q\right)\frac{nh\upsilon \:}{kT}\right)^{\frac{1}{1-q}}\right)}{\sum _{n=0}^{\infty }\left(\left(1+\left(1-q\right)\frac{nh\upsilon \:}{kT}\right)^{\frac{1}{1-q}}\right)}$

@MathematicalPhysicis