Cyclic cohomology of the Weyl algebra

We give an explicit formula for sp2nsp2n-basic representatives of the cyclic cohomology of the Weyl algebra HC
• (A2n)HC
• (A2n).As an application, we prove a generalization of a theorem of Nest and Tsygan concerning the relation of the Todd class and the cyclic cohomology of the differential operators on a complex manifold.