Sigma function solution of the initial value problem for Somos 5 sequences
Abstract
Description
The Somos 5 sequences are a family of sequences defined by a fifth order bilinear recurrence relation with constant coefficients. For particular choices of coefficients and initial data, integer sequences arise. By making the connection with a second order nonlinear mapping with a first integral, we prove that the two subsequences of odd/even index terms each satisfy a Somos 4 (fourth order) recurrence. This leads directly to the explicit solution of the initial value problem for the Somos 5 sequences in terms of the Weierstrass sigma function for an associated elliptic curve.
More typos corrected, and extra Proposition 2.5 added. To appear in Trans. Amer. Math. Soc
More typos corrected, and extra Proposition 2.5 added. To appear in Trans. Amer. Math. Soc