[ganessh]

In the calculation, F2n=Fn−1Fn+FnFn+1 =(Fn+1–Fn)Fn+FnFn+1 =FnFn+1–F2n+"FnFn−1" =2Fn+1Fn–F2n

in third line, it is FnFn+1

[richardkiss]

Good catch... fixed it. Thanks!!