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**riptorn70** I have a recursive function and I seem to be having a problem deducing a general solution for it:

$\displaystyle u_{n+2} = u_{n+1}^2 + u_{n}^2-2$

The initial conditions are $\displaystyle u_{o} = 1, u_{1} = 1$

Some of the values are as followed:

$\displaystyle u_{o}=1, u_{1}=1,u_{2}=0,u_{3}=-1,u_{4}=-1,u_{5}=0,u_{6}=-1,u_{7}=-1,u_{8}=0$

My initial thought was that it was a periodic function. But I am as yet unable to begin to formulate a general solution,

Can anyone help. Thank you.