Zadan je niz (an)nN0(a_n)_{n\in \mathbb{N}_0} takav da je a0=aa_0 = a, a1=ba_1 = b, gdje su aa, bRb\in \mathbb{R}, i

an=an1+an2,n2.a_n = a_{n-1} + a_{n-2}, \quad n \geq 2.

Odredite an2an1an+1a_n^2 - a_{n-1}a_{n+1}.