Number of unlabeled digraphs with loops (relations) on n nodes and with an even number of arcs.

A055973

Number of unlabeled digraphs with loops (relations) on n nodes and with an even number of arcs.

Terms

    a(0) =1a(1) =1a(2) =6a(3) =52a(4) =1540a(5) =145984a(6) =48467296a(7) =56141454464

External references