This site is supported by donations to The OEIS Foundation.

# Category talk:Somos-4 sequence

## Bilinear or quadratic?

Somos-4 sequence: bilinear recurrence of order 4 of the form

or equivalently

A function of two variables is bilinear if it is linear with respect to each of its variables. (Cf. Weisstein, Eric W., Bilinear Function, from MathWorld—A Wolfram Web Resource. [http://mathworld.wolfram.com/BilinearFunction.html])

Harry W. Braden, Victor Z. Enolskii, Andrew N.W. Hone, Bilinear recurrences and addition formulae for hyperelliptic sigma functions, arXiv (2005.)

It seems to me that it should be considered a quadratic sequence since it is quadratic in , although in the above mentioned arXiv paper it is considered multilinear (Why? I am confused here...) — Daniel Forgues 23:42, 17 October 2010 (UTC)