\(P^2=\dfrac{\left(2^2-1\right)\left(3^2-1\right)\left(4^2-1\right)....\left(2005^2-1\right)\left(2006^2-1\right)}{2^2.3^2...2006^2}\\ \)
\(P^2=\dfrac{1.3.2.4.3.5...2006.2007}{2^2.3^2....2006^2}=\dfrac{1.2007}{2.2006}\)
\(P=\dfrac{1}{4}\sqrt{\dfrac{2007}{1003}}\)