assuming k starts from 2... http://math.stackexchange.com/questions/265483/evaluating-the-infinite-product-prod-k-2-infty-left-1-frac1k2-r?lq=1
– Noam Shalev - nospoonAug 04 '15 at 21:07
1 Answers1
-1
The answer is $0$, since when $k=1$, $1-\frac{1}{k^2}=0$.