  Let an n-algebra mean an algebra over the chain complex of the little n-cubes
operad. We give a proof of Kontsevich's conjecture, which states that for a
suitable notion of Hochschild cohomology in the category of n-algebras, the
Hochschild cohomology complex of an n-algebra is an (n+1)-algebra. This
generalizes a conjecture by Deligne for n=1, now proven by several authors.
