(1+2/1) x (1+2/2) x (1+2/3) x .... x (1+2/26) x (1+2/27) =

2. (1+1/4) x (1+1/9) x (1+1/16) x ... x (1+1/4028049) =

let's denote the following product by:

thus we can come up with the following recurrence relation for the product:

so we can find iteratively.