# Another Combinatorial Summation!

$\Large{H_{q,s} = \sum_{k=0}^s (-1)^{s+k} 2^{2k} \binom{q-1+k}{2k} \binom{q-1-k}{s-k} }$

Generalize $$\large{H_{q,s}}$$ in terms of $$q$$ and $$s$$, and then evaluate the value of $$\large{H_{15,10}}$$.

Note: You may use a Calculator for the final calculation. Don't use the Scratch Pad.

×