Pfaffian Representation of Solutions to the Discrete BKP Hierarchy in Bilinear Form

A discrete BKP hierarchy in bilinear form is given. It is shown that the solutions of the bilinear forms are given in terms of pfaffians and the bilinear equations of a discrete BKP hierarchy are reduced to an identity of pfaffians. The N -soliton solution is explicitly constructed in terms of the pfaffian. As an example of nonlinear difference equations, a difference analogue of the Sawada-Kotera equation is given from the discrete BKP hierarchy.