Number of labeled digraphs without isolated vertices and with n arcs.

A121252

Number of labeled digraphs without isolated vertices and with n arcs.

Terms

    a(0) =1a(1) =2a(2) =25a(3) =520a(4) =15150a(5) =567540a(6) =25986334a(7) =1406214816a(8) =87803248260

External references