Number of labeled digraphs with n arcs for which every vertex has indegree at least one and outdegree at least one.

A121933

Number of labeled digraphs with n arcs for which every vertex has indegree at least one and outdegree at least one.

Terms

    a(0) =1a(1) =0a(2) =1a(3) =2a(4) =18a(5) =158a(6) =1788a(7) =23930a(8) =370886a(9) =6527064a(10) =128542420a(11) =2800362536a(12) =66858556196

External references