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# Category talk:Somos-4 sequence

${\displaystyle a_{n+2}\ a_{n-2}=\alpha \ a_{n+1}\ a_{n-1}+\beta \ {a_{n}}^{2},\,}$ or equivalently ${\displaystyle a_{n+2}={\frac {\alpha \ a_{n+1}\ a_{n-1}+\beta \ {a_{n}}^{2}}{a_{n-2}}}\,}$
It seems to me that it should be considered a quadratic sequence since it is quadratic in ${\displaystyle \scriptstyle a_{n}\,}$, although in the above mentioned arXiv paper it is considered multilinear (Why? I am confused here...) — Daniel Forgues 23:42, 17 October 2010 (UTC)