  We describe dualities and complexes of logarithmic forms and differentials
for central affine and corresponding projective arrangements. We generalize the
Borel-Serre formula from vector bundles to sheaves on projective d-space with
locally free resolutions of length one. Combining these results we present a
generalization of a formula due to Mustata and Schenck, relating the Poincare
polynomial of an arrangement in projective 3-space (or a locally tame
arrangement in projective d-space with zero-dimensional non-free locus) to the
total Chern polynomial of its sheaf of logarithmic 1-forms.
