Number of bipartite graphs with full rank

[simone at cs.york.ac.uk]

Dear seqfans,

I have the following question:

What is the number of nonisomorphic bipartite graphs on n vertices whose
adjacency matrix has n nonzero eigenvalues?

Thanks a lot for your time,
Simone

--
Simone Severini
Department of Mathematics and Department of Computer Science
University of York, YO10 5DD York, U.K.
Tel: +44 (0)1904 433072
Web: www-users.york.ac.uk/~ss54