We study an integrable case of n-particle Toda lattice: open chain with
boundary terms containing 4 parameters. For this model we construct a
B\"acklund transformation and prove its basic properties: canonicity,
commutativity and spectrality. The B\"acklund transformation can be also viewed
as a discretized time dynamics. Two Lax matrices are used: of order 2 and of
order 2n+2, which are mutually dual, sharing the same spectral curve.Comment: This is a contribution to the Vadim Kuznetsov Memorial Issue on
Integrable Systems and Related Topics, published in SIGMA (Symmetry,
Integrability and Geometry: Methods and Applications) at
http://www.emis.de/journals/SIGMA