Factorial function/Recursive formula for 2k-1/Exercise

Prove that for the factorial function the relationship

${}\operatorname {Fac} \,{\left({\frac {2k-1}{2}}\right)}={\frac {\prod _{i=1}^{k}(2i-1)}{2^{k}}}\cdot {\sqrt {\pi }}\,$

holds.

Create a solution